Had a good chat with your houseplant today?

 kw: book reviews, nonfiction, science, botany, research, plant consciousness, communication, signaling, plant movement, plant intelligence

In the human realm, "talking to the animals" like Dr. Doolittle is fictional. In the plant realm, it may be commonplace. What constitutes "communication"? There is more philosophy than science wrapped up in any attempt to answer that question. Even more so for the words "consciousness" and "intelligence". We may not have definitive answers in the next few decades, and perhaps we never will. In The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth, author Zoë Schlanger doesn't provide the answers, though some of those she interviewed offered nascent attempts at doing so.

The eleven chapters of Light Eaters delve into several strains of research that are on the verge of redefining what a "plant" really is and re-settling our understanding of the rôles plants play in the biosphere. As we find from numerous lines of research, plants have several routes of plant-to-plant signaling: chemical, electrical, acoustic, and possibly bacterio-genetic. Plants discriminate. They are found to send differing signals to siblings versus non-siblings of the same species; plants of one species can also "eavesdrop" on signals of another species. Furthermore, plants send signals intended for animal species! An example of the latter is the plants that emit a pheromone that attracts a certain species of parasitic wasp when a caterpillar that the wasp parasitizes begins chewing on the plant's leaves. It's rather like a youngster who gets attacked and calls on his older brother for help, but in this case the "older brother" is a different species. Plants getting chewed on also emit other volatile chemicals that alert nearby plants, which respond by altering the chemistry of their leaves to be distasteful or even toxic to the caterpillar.

These are examples of chemical signaling. Other stressors such as drought result in plants making tiny clicking noises as low-pressure bubbles collapse; it is similar to the popping knuckles most people engage in. It's hard for me to determine what kind of research showed other plants responding to these barely audible sounds, but Chapter 5, "An Ear to the Ground" presents the evidence. 

What about electrical signals? Within a plant, it has been found that cutting a leaf initiates a wave of electrical activity that sweeps through the plant. These images of a small plant leaf, taken just before a scissor cut, then one second after, and then seven more seconds later. The plant had been grown from seed containing engineered genes that cause the calcium channels (every cell has them) to trigger Green Fluorescent Protein (GFP) when they emit or pass an electrical signal. The electrochemical signal moves as a wave through the whole plant. These images were clipped from this video. If the video doesn't work (they can be ephemeral), search for "gfp plant signaling". This is just one of several.

As the narrator in the video explains, the signal moves through the whole plant in about a minute along the veins, and spreads from the veins throughout all the plant's tissues at a slower rate.

This got me thinking. We know that while an electrical signal in a metallic wire is very fast, roughly the speed of light, the electrochemical signals in animal nerves are much slower. I had the neural conduction speed measured in my arm one time, after an injury. It was 60 m/s, which is normal. The fastest neural conduction speed in mammals is about twice this, and some nerves, where speed is less critical, are as slow as the range 2-5 m/s. Plants don't have nerves; at least none that we can recognize. But the veins seem to have a similar function, albeit slower, in the range of about 1 mm/s. That is between 2,000 and 120,000 times slower than animal neurons.

Put that together with a statement later in the book. The author had a hint of an idea (one I was toying with as I read): What if we think of the entire plant as a brain? She asked one scientist, who said, "I think you're right. I just don't talk about it." Let's speculate a bit. If you get jabbed in the leg with a pin, you'll react within about a quarter of a second. In the little plant shown in the video, which is about 10 cm across, the signal "I've been cut!" reaches the whole plant in less than two minutes. The "reaction" of the plant is to begin to synthesize noxious chemicals in the leaves, which takes a few hours. From this we can extract a couple of ratios:

1. We can infer the signaling time between your leg and brain as about 1/30 second. If signaling through the plant took 100 seconds, the ratio is 3,000:1.
2. Your physical flinch and "Ouch!" begin after about 1/4 second, while chemical synthesis in the plant gets underway in an hour (3,600 sec), for a ratio of 14,400:1.

If, then, the whole plant is, or contains, a distributed brain, it runs several thousand times more slowly than an animal brain. This is in accord with the rate that twigs grow on many woody plants, compared with the rate of animal motions. Animals move at about "the speed of gravity", by which I mean that rapid animal motions, such as swatting at a fly, happen at speeds similar to that of an object dropped a meter or so. Time-lapse videos of plants either growing or "doing" various things, such as the "reaching" of bean tendrils for something to cling to, show their motions to be hundreds to thousands of times slower than animal motions. It seems plausible that, if plants "think", they do so correspondingly slowly. While we cannot consider plants to have a nervous system, perhaps a term such as "signal conduction system" or "signal transduction system" can be used.

Do they think? Plant "intelligence" has been a fiercely contentious issue for decades, and that doesn't seem to be slowing down. Focusing on just three things: speed of motion, speed of communication, and speed of reaction, I (and, I think, Ms Schlanger) consider plants to be doing most things animals do, but on a time scale around 10,000 times slower. If we learn to talk to plants, and to hearken and understand what they are saying, we'll need enormous patience. Perhaps a translating SI (simulated intelligence) application can craft a signal at a rate the plant can accept, patiently receive its reply, and signal a human (who is doing something else in the meantime, because it could be hours) to come "read" the response. Even if the human then requires several minutes to decide what to say next, to the plant, the signal coming back, through the app, seems to begin almost instantly.

Finally, do plants see? Plants that mimic neighboring species hint that this is so. How can a South American vine Boquila take on the appearance of at least a few dozen other plants, just by growing in the vicinity? Moreso, if part of this vine is near one kind of plant, and another part is near another, it mimics both! To a lesser extent Mistletoe plants do something similar. One researcher believes the "signal" received by a Boquila plant is not visual, but bacterio-genetic, some kind of genetic signal from the neighboring plant's cloud of symbiont bacteria. All animals and all plants are inhabited by and surrounded by their own microbiome. Each breath we exhale contains members of our microbiome. Your own bacterial "envelope" changes every time you make a new friend and begin spending lots of time with him or her. The author finds a visual hypothesis more parsimonious, and I agree. Plants do have photoreceptors; they are chloroplasts. There are also other colored bodies in plants, in colors other than green. They may also receive light as well as reflect it, or they may provide color filters for chloroplasts to detect colored light. The author points out that this is similar to cuttlefish, which have color-blind eyes, yet they can still mimic the patterns and colors of the surface they are sitting on, probably because their whole skin surface is covered with photoreceptors that must provide the color signal.

I suggest a "red hat" experiment. Start with a number (12 at least) of plants that are wired to detect stress. Once they have recovered from being wired the experiment begins. Whenever the person who cares for the plants wears a red hat, that person also takes a snip from the end of one leaf of half the plants, chosen by a prearranged formula, and let some of the plants never be snipped. Let the interval between snipping incidents be a few days. I conjecture that after a few weeks at most, the plants will all react whenever the caretaker enters wearing the hat, before any snipping is done. This should indicate something visual on the part of the plants. It is likely that the never-snipped plants will react differently from the others. However, it is always possible that the caretaker is in a different mental state on "snipping days", and this causes an airborne chemical signal that the plants can detect and react to. I am not sure how to control for that.

Plants are fascinating, even more so now to me, after reading this book. What a great read!

-----------------------

A couple of quibbles and contentions:

1. On p 39 the author coined the adjective "Descartian", referring to René Descartes. The adjective "Cartesian" already exists and is easier to say.
2. On p 156 we read, "In the United States alone, as many as 11,000 farmworkers are fatally poisoned by pesticides each year, and another 385 million are severely poisoned…". 'Scuse me, but the entire US population is about 360 million, of whom two million are farmworkers. The CDC states 10,000-20,000 "poisonings" without saying how many are fatal. Sundry reports are all over the place. One appears to be the author's source for 11,000 fatalities yearly, while another states that 60,000 nonfatal incidents occurred in five years, or 12,000 per year. The author needs to dig a bit deeper.

Give it to me straight, Doc

 kw: book reviews, nonfiction, science, publications, research, fraud, bias, negligence, hype, polemics

When I was a chemistry major, taking organic chemistry, we had a lab exercise called The Martius Yellow Competition. It's a famous experiment, designed at Harvard, in which we had to produce seven compounds, one of which was the famous dye Martius Yellow. The dye is protein-specific, making it useful for staining certain cell preparations for microscopy. That also makes it problematic if you get it on you. It stains your skin bright yellow, and the stained skin takes about a month to grow out. A few of my fellow students finished that lab day with big yellow blotches on their hands and even faces.

What is of interest here is that two of the compounds—all are crystalline solids at room temperature—are hard to crystallize. To get one of them to precipitate out of solution, we had to cool the solution on an ice bath and then scratch the bottom of the flask, carefully, with a metal spatula. The other needed exposure to UV light, which we accomplished by putting the flask on a window sill for an hour or so.

Of course, if you already have a little bit of the target material on hand, in crystalline form, you can get a solution to crystallize quickly by seeding it with a bit of dust from crushing a tiny crystal of the same stuff. And here the professor told us a story. One of his mentors was an elderly chemist who had a beard. Once in a while one of his students would be having a hard time getting a solution to crystallize. He would call the professor over for advice or help. The professor would look at the flask, scratching his beard, and then the desired crystals would begin to form! As we heard the story we first thought the old professor must have poor hygiene habits. But No: Then he told us the old fellow knew what to anticipate, and early in the morning of such a day, he would put a bit of solution on his beard and let it dry. The scratching would release a few seed crystals into the air. When any of them fell into the flask in question, it would start the crystallization!

Such playful tricks aside, during my extended education (14 years at four universities and colleges), I learned that some scientists play fast and loose with their "science." Not all published "science" is genuine, and some of it is downright dangerous. I knew professors who were, quite simply, frauds. I don't wish to mention any names, because others have already exposed the worst of them, or their "work" has been superseded anyway. But I learned that there are several ways to get results into print even if you have no useful results to report. It's the fruit of the perverse motivation system called "Publish or Perish".

Thankfully, I don't need to get into detail, because a real scientist, Dr. Stuart Ritchie, has written a great book about how science goes wrong: Science Fictions: How Fraud, Bias, Negligence and Hype Undermine the Search for Truth. Dr. Ritchie is a real scientist, in contrast to myself: I got the degrees, but spent almost half a century writing software for scientists, without doing any science. Much of my value was making sure they got their math right, because I remembered all the calculus they had forgotten. I am particularly adept at statistics, so I know deeply how easily they can be misused to cook up a result almost out of thin air.

As an illustrative aside: I am an amateur radio operator (a Ham). On one occasion the members of a radio club I was part of visited an amateur who specialized in moon-bounce communication. He had a steerable antenna the size of a barn door, fed by a thousand-watt transmitter. It was just barely capable of getting a signal to the Moon and hearing it when it came back. The signal was noisy and barely discernable above background noise. Sometimes a Morse code "dah" would be broken up and sound like two "dits". (The dah is three times as long as the dit). Our host told us that sometimes the signal is so buried in the noise, and you listen so hard, that you can imagine an entire conversation out of random noise.

This is relevant. Many, many published results are based on something called "statistical significance", which has a criterion called the p value, with a "significance threshold" of 0.05. As long as the p value is less than 0.05, the result is considered "significant". It requires backward thinking to understand a p value. It is the probability that the "result" you obtained could have happened completely at random. Sometimes you will hear it said that there's only one chance in twenty, or less, that the conclusion you have drawn is incorrect.

That is not a very strict criterion. If you peruse scientific literature that includes statistical analysis, you are likely to find that most of the papers show results with a p value only a little below the threshold: 0.048, 0.04, 0.045, and so forth. Sometimes a "more robust" result will be reported, with a p value of 0.01 or even 0.005. To me, that is more like it. Because if you have thirty or so publications, all touting a p value just below 0.05, you have to say to yourself, "At least one of these is likely to be false. Maybe more than one." Then you should ask, "How can I find out which?"

The "how" is to replicate the experiment. Some experiments aren't too hard to replicate. What if the new experiment gets a different result? You can't stop there and say "It was wrong." It requires digging deeper, and nailing it down, then finding a journal to publish your counter-article (which can be remarkably hard; see the author's first story). In Science Fictions you'll read about some of the ways one can follow up.

What is more serious is the practice of hiding results that didn't work out, often called Null results. This is called the File Drawer Bias. For some kinds of experiments, particularly in psychology and medicine, there may be five or ten times as many "results" in the file drawer as the ones that were published. Automatically, we have to realize that a quarter to a half of the published reports are probably incorrect. Again, replication might be able to clear the matter up. However, doing experiments takes time and money. Our author reports a partial solution that is being implemented by many funding bodies, both governmental and private: They will only support the experiment if it is pre-registered and the results are guaranteed to be published. Such as system can still be gamed, but it is harder.

All this shows up close to halfway into the book, where the author tackles the issue of Publication Bias. Earlier, he takes on Fraud, as the most dangerous, and paradoxically, often the hardest to deal with in any timely way. A few heartbreaking stories are told, such as a surgeon who claimed he had perfected an artificial trachea to replace one damaged by accident or cancer. All of his patients died, usually after only a few months. Yet he was protected by the institution where he worked because of his fame. But eventually it all blew up. Far too many charlatans get famous enough (based on little substance!), that they are protected this way. And let us not forget the "accepted science" of the late 1700's, which resulted in the physicians for retired President George Washington bleeding him nearly dry because of a bad cold, such that he died.

Fortunately, we are more likely to encounter various kinds of bias. We are all biased. I was fortunate enough to take a class in literary discernment (I don't recall its actual title). We read articles from a great many publications. Some journals that I remember were The Wall Street Journal, Commonweal, National Review, The New Republic, The London Times, and The New York Times. We learned that every writer is biased, as is every editor. We learned to determine the bias of each writer and, from multiple articles, the likely bias of the editorial board for some of the publications. We also learned how to tell if a writer or editor is aware of the bias and has tried to mitigate it to any degree. Hint: Look for the number of modifiers (adjectives and adverbs) and their "flavor" (for example, "The company reached a compromise with the plaintiff" compared to "…reached a risky compromise…" or "…reached a satisfactory compromise…", and also compare to "…barely reached…"). Honest editors remove as many modifiers as possible, keeping only those that bear their weight in meaning.

I don't know how much Negligence is a problem. The stories didn't stick with me. Hype was of greater interest. Who remembers (from 1989) Cold Fusion? Lots of hype. Eventually, a total fizzle. The first story in the "Hype" chapter of Science Fictions tells of a supposed bacterium that used arsenic instead of phosphorus in its biochemistry. It turned out to be a story of contamination in the lab, not novel biochem in the field. It seems to be accepted today for a scientist with any kind of result to issue a press release long before submitting an article for peer review and publication. Perhaps the Snake Oil guy above would fit better alongside this paragraph!

But, seriously, what, oh what, can be done about it? Dr. Ritchie knows science from the inside. His last two chapters plus the Epilogue have suggestions that look workable to me. They primarily deal with incentives. Some of the current incentives seem designed to reward bad science. The simplest example is the Publish or Perish atmosphere in which tenure is only to be had by publishing at a superhuman level. This rewards "salami slicing", in which work that has several results will be published as several small papers rather than one that links them all together.

A family proverb is the "Moses method": To change the system, get everyone into the wilderness and wait 40 years for the older generation to die off. I hope the suggestions of Dr. Ritchie can make great inroads into the mess we are presently in, a lot quicker than 40 years.

Special bonus feature:

I sometimes tell scientists I know my suggestion for getting lots of good science done:

• Do a sketchy experiment to test an outlandish hypothesis. Drag it out until you get some kind of publishable result.
• Publish, with much fanfare.
• Based on the publication, trawl for funding to do more experiments to "confirm" your finding.
• Publish again; two papers if possible. Many more, if you can.
• Produce plenty of fanfare, including "stick in your eye" statements to rile up the establishment.
• Repeat as much as possible or until you can't get more funding.
• Some angered scientists will publish rebuttals. Some may even try to replicate your result.
• Answer every rebuttal, vociferously, in multiple venues if possible.
• Publish a "synthesis" of the entire matter. Be sure to cite all your prior work. Your "citation index" gets you noticed more.

This will get a lot of scientists to work their butts off to prove you wrong. One side effect is likely to be some unexpected, good science. Then, if you want to retain a shred of reputation, publish again, "de-biasing" your results, with more modest conclusions and a bit of mea culpa about the "little bit of overreach" in which you formerly indulged.

And now, back to our regularly scheduled program. It's a great book!

The other kind of land snail

kw: species summaries, natural history, natural science, museums, research, photographs

I spent more than two years, in my work at the Delaware Museum of Natural History, cleaning up/correcting and loading data for their collections of terrestrial gastropods, informally known as land snails. Correction: the past 2+ years I worked with the pulmonate terrestrial snails. They are called "pulmonate" because they have lungs, though really they are modified gills in an internal cavity where they can be kept moist, and muscular contractions pump air in and out, like real lungs.

That is not the only kind of land snail. The other great division is the operculate terrestrial snails. They are called "operculate" because they have an operculum, a kind of door that they can use to seal the shell shut, to keep water in, because they have gills inside the shell, and also to keep predators out. Many marine snail species also have an operculum, used to avoid desiccation when they get stranded above the tide line for a while, and even more to keep predators out.

The pulmonate lifestyle is apparently the easier, because there are many more species of pulmonates than operculates. In the DMNH collection, 95% of the land snail collection is pulmonates, more than 40,000 lots versus about 2,000 lots or operculate land snails.

Thus, my last project is to clean up, and load, all the data for the operculates. The first major family that I encountered is the Annulariidae. Many of these have a flared aperture, as shown in these two images:

This image is roughly life size (the museum label is 3" long). The species Chondropoma bairense Torre & Bartsch 1938 is a little prettier than most of its kin, and larger. Here, "Chondro-" relates to "grain", and many species in this genus are little larger than grains of corn. The flared aperture is characteristic of species in many genera of the Annulariidae.

This one is called "bairense" because it was first found at Baire, Cuba, which is in the south, in the state of Santiago de Cuba, west of Guantanamo. Hoyo de la Reyes can mean "king's pit" or "-hole", but here it probably refers to a steep valley.

From the differences between the older label and the one that C.L. Richardson typed up we can see why it is helpful to have all the labels possible with a specimen. Richardson simply left out the name of the town on his own label!

Here is a closeup of the shells. Sadly, both have their tips knocked off. This is the only lot of this species in the DMNH collection, so we must make do with what we have. I find it fascinating that there is ribbing along the outside of the whorls, but the shell on the right also reveals longitudinal ridges in the omphalos (a synonym of "navel" or belly-button; it refers to the central hole where the whorls come together. Not all snail species have one, including the next one shown).

I picked one other species to show, because of its bristly appearance and because one shell still has the operculum:

In spite of the way the name is spelled on both labels, this species is Blaesospira echinus (Wright, 1864). The parentheses indicate that the genus name has been changed, but I don't know the history. I don't know what the genus name means, but I suspect it means something like "open spiral" because the whorls of the shell are not in contact.

The species name is easier: "echinus" means "spiny", and this little critter is truly spiny. The mogote (isolated hill) named "El Queque" is a well known snail collecting locality in the Viñales area of the state of Pinar del Rio, Cuba. 

This image is about 40% larger than life size; the shells seldom exceed a centimeter in length or diameter. These spiky little critters are even more impressive when magnified:

Here you can see that one of the shells still has an operculum in its aperture. Opercula frequently have a spiral structure like this one. The wavy rim of the apertures hint at the way the spikes are formed. They are hollow with open tips. These lovely little shells are very popular with collectors, which makes me wonder if they are still to be found there. Few specimens from Cuba have found their way into American collections since the Castro regime began in 1959.

I should also mention that some taxonomists place this genus in the family Pomatiidae (once called Pomatiasidae). What with DNA sequencing and other tools of molecular biology, the taxonomy of mollusks in general is being reviewed and revised more than ever. 

Eat 'em and weep

kw: book reviews, nonfiction, food safety, research

Three stories about writing style:

Story 1: In one of his memoirs, prolific author Isaac Asimov writes of the article he wrote titled "The Endochronic Properties of Resublimated Thiotimoline". It was a spoof, written for a purpose: he had been a published author of popular hard science fiction since he was 19, and he was wondering if he could write in the stodgy, hyper-objective style he would need to use for his doctoral dissertation in Chemistry at Columbia University. The article was as stodgy and hyper-objective as he could devise. He published it in Astounding, figuring that would be sufficient cover. His dissertation passed muster, but unbeknownst to him, his professors had read the article also. When they called him in to announce their (favorable) decision on his degree, the chair of his dissertation committee said, "Greetings, Dr. Asimov! Please tell us more about Thiotimoline."

Story 2: I worked a little more than two years as a machinist in the Physics shop at Cal Tech. We were building a precision radio telescope antenna; it was 34 feet across (10m), and had to be accurate within a few thousandths of an inch (100µ). During the final shaping of the parabola, the assembled dish was mounted on a rotating air bearing 8 feet across (2.4m). It spun slowly, as a specially constructed device cut into the aluminum honeycomb surface, a couple of mm per cut, as it was advanced up a specially-shaped track. Each cut took a full work day. I had to babysit it while the master machinists worked on other things, every day for a few weeks. Because machining uses hearing more than sight, I could move about the room, a huge space in which the mirror for the Palomar Telescope had been polished, which had later been half-filled with a synchrotron, a kind of atom-smasher. I found a cabinet filled with draft copies of PhD dissertations, based on research done using that synchrotron in the 1960's. This is all background: I have the kind of mind such that I can read, with some enjoyment, stodgy, hyper-objective dissertations, which is what I did for most of those few weeks.

Story 3: My brother had been a working artist, primarily a calligrapher and calligraphy instructor, for more than 20 years. The art market was slowly shrinking in the late 1990's, so he decided to return to school, get a Doctor's degree, and, he hoped, become a museum curator or professor. He first completed a Master's in Art History. However, he also was a published author, of nonfiction books, with a very readable writing style. Not having published his own "Thiotimoline" article, he had nothing he could use to convince a dissertation committee that he could write in a style appropriate to a history dissertation. So the History Department declined to admit him to a PhD program. One of them told him privately that the professors were embarrassed that their writing was so bad by comparison to his. Fortunately, a different department requested that he apply, and he was admitted. He received a PhD at age 50 and is now a professor.

I find in the book Did You Just Eat That: Two Scientists Explore Double-Dipping, the Five-Second Rule, and Other Food Myths in the Lab, two scientists who are moving in the other direction. Paul Dawson and Brian Sheldon studied various food myths with their students at Clemson University (Dr. Sheldon is now at N.C. State U). They studied myths about the 5-second rule, Beer Pong, restaurant menus, jet-air hand dryers, and several other things. Being professors, having written their own stodgy, hyper-objective dissertations, they are moving into the public arena. This is not unusual…but this book is unusual, in a good way.

This book is unique in my experience, being a mix of about 2/3 very refreshing text for the general reader, and 1/3 stodgy, hyper-objective reporting of their experiments. I have read many popular books in which the results of scientific experiments are discussed. This is the first such book in which every experiment is described in the kind of detail you'd find in a technical research report. The authors are kind enough to warn us about this in their Introduction, and to set off the stodgy stuff with "Science Stuff Ahead"; they give permission to skip these sections, to anyone who finds them too stultifying. Thus, for example, a few sentences from their chapter about the germs found on restaurant menus:

Swab-samplers (made by 3M Swabs, 3M Company) were used for menu sampling… The restaurant menus sampled fell into three general sizes of around 603, 768, and 1,207 cm². … Back in the laboratory, sample tubes containing the swab and sterile 0.1 percent peptone water were vigorously shaken by hand...

From the descriptions, and sufficient budget, and an army of willing students, you could reproduce each experiment exactly. That is why the writing is the way it is. Of course, I can read this stuff just fine, but most folks can't; the MEGO factor can be huge!

Let's cut to the chase. Is the 5-second rule true? ("If you pick up dropped food in less than five seconds it is still safe to eat.") Is it? How would you define "safe"? The outcome of the experiment, in which several kinds of food were dropped onto tile, wood, and carpet inoculated with a harmless variety of Salmonella, the most common cause of food poisoning, was that "safe" really just means "maybe a little bit safer". In general, if you can grab that grape in one second, it will have fewer bacteria on it than if it takes you 4 seconds, and if you wait, say, half a minute, there will be even more. But the number of bacteria transferred was never Zero. However, by this measure, carpet was "safer" than tile or wood. That is the opposite of what I'd have expected.

Consider this, though, based on other experiments: How many bacteria get on your food from your own hands? How thoroughly and carefully do you wash before handling food? Prior to washing, after almost any amount of daily activity, our hands are as dirty as the floor we are walking on, whether or not we wear shoes indoors.

Rather than be a spoiler about the results in this book, I will instead invoke a forensic principle, known for at least a century, as it applies to the transfer of germs (bacteria, fungi, viruses, and parasites) to and from our food and everything it touches: When two surfaces come into contact, material from each surface is transferred to the other. Numerous criminals have been convicted in part because, not only were their fingerprints found "at the scene", but, if they brushed against the wall, tiny flakes of paint from that wall got on their clothing.

To sum up, if anything touches food, we must assume it will contaminate the food unless steps were taken ahead of time to remove all contaminants. So, if you're going to enjoy Beer Pong, make sure you have really good medical insurance!

The waxy snails

kw: species summaries, natural history, natural science, museums, research, photographs

In the course of time I have come to a cabinet-and-a-half containing a couple of thousand lots of a family of snails (gastropods) named Cerionidae. Though there are four genera in the family, the Delaware Museum of Natural History holds members only of the type genus Cerion. The family was split out from a large family, Urocoptidae, by Henry A. Pilsbry in 1901. "Harry" Pilsbry spent much of his career at the Academy of Natural Sciences in Philadelphia, where he described hundreds (thousands?) of new species.



This first photo is of the type species (of the type genus of the family Urocoptidae), Urocoptis cylindrus (Dillwyn, 1817). Lewis Dillwyn originally named this species Turbo cylindrus, using a genus name created by Carl Linnaeus in 1758, when he single-handedly invented biologic nomenclature. At the time these specimens were collected the species was considered of the genus Cylindrella, then was shifted again to the genus Urocoptis when the family Urocoptidae was set up. The family Urocoptidae contains many genera, and while many of the species are similar to this one, being cigar-shaped with a flaring aperture, they vary a lot around this gestalt.

The genus Cerion, pronounced "kerion" or "Syrian", from the Latin word cerea, meaning "waxy", was named by Peter Röding in 1798, based on his renaming of Turbo uva as Cerion uva (Linnaeus, 1758). The genus has just a handful of fully accepted species, but the DMNH collection contains representatives of more than 200 species, which have varying levels of acceptance among workers carrying on a decades-long reworking of land snail families. This photo shows two characteristics of many Cerion species: the off-white waxy color and the ribbing along the entire shell. The flared aperture is less pronounced than it is in most of the Urocoptidae. The following photos showcase three more Cerion species, chosen to illustrate the range of variation in the genus.



The photo below shows Cerion weinlandi (von Martens, 1860); Edward von Martens originally placed it in the genus Pupa. It does look like a pupa! I chose this species to illustrate the extreme of nearly absent ribbing. Also, while the background color tends to be waxy off-white, this species is one of many with color banding and mottling also.



Though this lot is labeled Ceriod dalli Maynard—publication date is probably 1889—it was renamed and included in the species Cerion rubicundum (Menke, 1829). I don't know what name Karl Menke originally gave it. The species name means "ruddy", and when the shells are fresh and moist, the brown markings are reddish-brown. I chose this species for its narrow ribbing.



Finally, Cerion marielinum Pilsbry, 1927 (the museum curator attributed the species to Carlos de la Torre, who had edited the journal in which Pilsbry published the description) is so named for its occurrence mainly near Mariel, Cuba. This species shows wider, more robust ribbing, and also has a ruddy background with the waxy white being confined to the tops of the ribs.



I chose the scale for these photos so that they would show the shells close to life-size on a 17-inch monitor. On my 22-inch monitor they are about 25% larger than life. Comparing the four Cerion species with Urocoptis cylindrus, there is certainly a resemblance. It is easy to see why the genus was originally put in the same family. However, details of their morphology, including not only the more pronounced ribbing, but also the smaller aperture and the small teeth inside the aperture, distinguish Cerionidae from Urocoptidae…at least for now! Biological naming is always a tug-of-war between "splitters" and "lumpers". In some mollusk families, large numbers of species have in recent years been combined into a relative handful of species, and this may soon result in the few hundred species of Cerion being lumped into a smaller number of species that are recognized as being rather variable.

Genetic studies and breeding studies are going on in parallel, and revealing more and more about the species and inter-species relationships of many animals, not just snails. But, you know, I just like opening a drawer full of shells once in a while to simply admire them.

Some random members of family Orthalicidae

kw: natural history, natural science, museums, research, photographs

I have been in the midst of inventory of terrestrial snails of a large family that is popular with shell collectors, the Orthalicidae. The family is named for the genus Orthalicus, but the family contains numerous species in many genera. In recent years taxonomy professionals have split certain genera out into new families. But we tend to call all these species "Orthalicids". Today I just present a few that I ran across recently, showing some of the breadth of attractive shell forms in these families. Each image is followed by a caption.

These are two species in the genus Placostylus, P. scarabus (Albers, 1854) and P. seemani (Dohrn, 1861). They are found on the islands of the south Pacific: the former in New Caledonia and the latter in Fiji. These island nations are about 850 miles apart (~1,350 km), so there is little natural opportunity for these species to encounter one another. The Fijian shells are visibly narrower than the Caledonian.

These are two more species of Placostylus, P. strangei (Pfeiffer, 1858) and P. stutchburyi (Pfeiffer, 1860). Both are found on the Solomon Islands. The third row consists of five lots of shells that have been identified as Placostylus, but no species is yet assigned. I am particularly intrigued by the one shell with aperture showing, that is bright orange inside.

This closeup shows one lot of P. scarabus. I purposely turned one shell to show the aperture, which shows a pale orange inside, less prominent than the one in the former picture. This also shows the variety of coloration to be seen in a single species, from quite mottled and brownish to smoothly creamy.

I turned two of these shells, of the more distantly related species Auris melastoma (Swainson, 1820), to show the nearly black interior. "Melastoma" means "black mouth". These inhabit Brazil.

Finally, this is a closeup into the plastic box containing one lot of Berendtia taylori (Pfeiffer, 1861). These are from a little closer to home, for us Americans at least: on the Baja peninsula of Mexico. I wanted a closeup of these, to show the fine ridges that cover the shells. You can also see a relic of museum practice in three of the shells: Munroe Walton had written his own number inside the apertures, and these have been crossed out and the DMNH catalog number written there.

The most popular snails

kw: species summaries, natural history, natural science, museums, research, photographs

For the current series of projects at the Delaware Museum of Natural History, I have worked through several families of terrestrial gastropods (land snails and tree snails). Many of these are quite inconspicuous, being small and not colorful, though they are in general a little more various than the little brown "mud snails" (freshwater gastropods) I worked with for most of 2016.

You know, in any group of creatures, most are rather inconspicuous and poorly known. The "typical" mammal is a "little brown furry thing" such as a mouse, vole, shrew or lemming. The "typical" bird is a "little brown feathered thing" such as a wren or sparrow. The "typical" insect is a "little dark beetle" about the size of a grain of rice. The world is full of little brown things and we hardly notice them.

But we really like the colorful "charismatic" ones. Among the land snails, that would be the tree snails of Florida and the Caribbean, of the genus Liguus.

This is part of a drawer of "unidentified" lots of Liguus fasciatus, the poster child for pretty tree snails. Though these have been identified as to species, L. fasciatus has many "forms" or "varieties", which we provisionally catalog as subspecies, but they probably aren't really subspecies. We usually call them color forms.They hybridize freely, but a particular color form is usually physically separated from most others, being endemic to a few "hammocks", as small patches of raised and heavily vegetated ground are known in the area.

These are mostly from an area of the Everglades called Pinecrest, named for a ghost town tucked away in the middle of a couple of hundred hammocks. You can clearly see that most of these lots are in need of splitting into their color forms. Any particular hammock may be inhabited by a few color forms. A collector in a hurry will gather a couple of dozen shells, put them in a box or bag with a label (date, provisional ID, and location, at the least, to be a useful specimen lot), and move on to the next hammock a few minutes' walk away in the dry season, or a short airboat ride away the rest of the year.

Here is the prettiest of the color forms, in my opinion:

On your computer screen this may be a bit larger than life size. The paper label is 3 inches long, so these shells are about 2 inches long, a little bigger than the average for the species. Liguus fasciatus splendidus Frampton, 1932, must have been Henry Frampton's favorite also. These are indeed splendid! This lot was collected by Erwin Winte a few years after Frampton described them, and in the 1980's it wound up at DMNH.

These shells are so sought after that, though they are prolific and widespread, many color forms are getting hard to find. In the southeast U.S. and the Caribbean, a whole subset of shell collectors are called "Liguus collectors". We are loving them to death!

This only serves to introduce these lovely shells. I hope soon to gather pictures of several color forms, and also to compare L. fasciatus with its sister species in the genus.

The referential Clausiliid

kw: species summaries, natural history, natural science, museums, research, photographs

The gathering of biological species into genera (plural of genus), and of genera into families, can be a difficult matter. This is particularly true of animals that are variable in their expression, including mollusks, and gastropods (snails) in particular. The history of discovery proceeds to-and-fro: Species after species will be collected and described, and at first, many similar creatures will all be described under a certain genus. A later researcher may then distinguish a common set of features for certain of those species, and a different set of features for others, leading to setting them aside as a new genus. A similar but more arduous process is needed to discern family membership…usually.

In the case of a unique family of terrestrial snails, the Clausiliidae, one and only one distinguishing feature is needed to determine whether a newly discovered species belongs: the presence of a clausilium. This requires a little explanation.

You may know that many marine snails have a kind of "door" that they can shut behind them when they retreat into their shells. It protects them from many predators and also keeps them from drying out when they are exposed to the air for too long. These two pictures show different species of whelk; the operculum for each is visible. First we see a Lightning Whelk all pulled inside after a wave threw it up onto the beach. Its operculum is the brown oval thing in the aperture.

The second photo shows a different species of whelk crawling on the sand. The animal's foot, at the lower left, is white with dark spots, and the operculum is also brownish, attached atop the end of the foot. Many, many families of marine gastropods have opercula (the plural of operculum). Twenty families of freshwater gastropods also have opercula, as do a small number of non-pulmonate (that is, gilled) land snails. Only one prominent family and two very minor, though related, families of pulmonate land snails have opercula. A pulmonate snail has a lung rather than gills, or in addition to gills, and can thus spend prolonged amounts of time out of the water.

A clausilium is not an operculum. This structure is not kept external to the shell, as an operculum is, but is internal, as seen in these semi-transparent shells. Rather than being attached to the animal's foot, it is attached by a muscular structure to the columella, the central column around which the whorls of the shell are wrapped. When a Clausiliid snail retreats into its shell it pulls its body inside, then deploys the clausilium to block the aperture. So the clausilium's purpose is the same as that of the operculum, but is a distinct evolutionary development.

In addition, whereas an operculum is sometimes thin and even translucent, it is usually robust and may be a thick shell in its own right with a spiral structure. By contrast, a clausilium, although always calcareous, is thin and rather fragile. Apparently, members of the Clausiliidae, being small and having a small aperture, do not encounter the determined predators that attack many marine snails.

Today in my work on the current project at the Delaware Museum of Natural History I began to take inventory of a little more than 1,000 lots of the family Clausiliidae. The type genus of the family is Clausilia, described by Jacques P.R. Draparnaud in 1805. He based his description of the genus on the species Clausilia dubia, but a later evaluation by physician and malacologist Louis C.G. Pfeiffer led to a re-description of the genus as referred to Clausilia scalaris Pfeiffer, 1850. Ironically, this species has been renamed and then made synonymous with another species, and is now called Muticaria macrostoma (Cantraine, 1835; Cantraine originally called the species Clausilia macrostoma).

I found that DMNH has just one lot containing shells of this species, which is endemic to the island of Malta. The collector, whose material was obtained by Ralph Jackson in the 1950's and later donated to the museum, notes that this species is "very rare". Yet he somehow obtained six shells.

This photo shows the shells close to natural size. It is hard to see in this image that the shells are well-decorated with ridges or striations. Clicking on the image to see it larger is a little better, so I also took a closeup through a low power microscope.

The species name "macrostoma" means "large mouth". Clausiliids all have small apertures, and the aperture of this species is only "large" by contrast to many other species in the family, and that primarily because of the wide lip around the "mouth".

All the shells in this lot have the first one or two or three whorls broken off. That fact and the ridges indicate that these little animals live in a rather high-energy environment. I became curious about the locality so I looked it up, and found that Mistra is on a protected bay. Malta is not very large, being 17 miles long and 8 miles wide (27x13 km), but it has room for at least five places named "It-Torri", which means "red tower". The nearest to Mistra is about three miles to its northwest. This is a much windier locale than Mistra, so perhaps such environmental stresses shaped the species.

Few clausiliids are so heavily decorated, and, indeed, most are smooth or nearly smooth. So it is ironic for this to be, in effect, the "poster child of the Clausiliidae."

The yellow-tipped little agate snail

kw: species summaries, natural history, natural science, museums, research, photographs

Earlier this year I completed two major projects to prepare about 17,000 data records at the Delaware Museum of Natural History for all the freshwater species of bivalves (clams and mussels) and gastropods, and load them to a new database system from which they can be served up via the internet. The principal portal is iDigBio. A secondary portal, from which it is easier to dig into the records on a museum-by-museum basis, is InvertEBase. Each project took about a year.

That done, I have begun working through the museum's data for terrestrial gastropods (land and tree snails), which total about 38,000 records. We decided to take these a cabinet or two at a time, for the most part. I am basically tackling between 1,500 and 2,000 records per mini-project. A first project took about a month, so I expect the sum of about 20 projects to take a couple more years, maybe three or more.

I am in the midst of inventory for three related families, and the first is Achatinellidae. These snails were so-named because they resemble the large tree snails of the family Achatinidae. The prefix "achat-" means "agate" in Greek, and refers to the striped appearance of the most familiar species, the giant African tree snail, Achatina achatina (Linné, 1758), also called the tiger snail.

The one shown in this image may have a shell as long as 8" (20cm). The suffix "-ell" means "small"; the snails of family Achatinellidae are much smaller than the Achatinidae, but many have a similar striped look.

The type genus (the one the family's description is based upon) is Achatinella, and the type species is Achatinella apexfulva (Dixon, 1789). As I was taking inventory of the specimen lots of this species, I noticed that some had been collected by a major donor to the museum, Munroe L. Walton, when he was quite young, not more than eleven years old. In the three photos below, you can see they were collected in Hawaii in 1901; Walton was born in 1890. First, the photos, which mostly speak for themselves. Commentary continues following.

Around the year 1900 it was common to distinguish the many color variations of variable species by assigning subspecies names. The original labels for the first two lots reflect this. The third lot was originally attributed to a different species because many of the shells in certain parts of Oahu are left-handed, such as the one on the right in the third picture. These are now recognized as part of the species apexfulva. The suffix "-fulva" means "yellow", and shells of this species have a yellow tip. Specimens of this species grow to 1.5-1.9 cm (0.6-0.75 inch).

The second lot shown has an added label, written by Edward W. Thwing, who may have been the actual collector of that lot or part of it. He was 22 years older than Walton. The designations "New." and "Newc." on some of the labels refer to Wesley Newcomb, a physician who became a curator of mollusks at Cornell in the 1870's and until 1888. He described the first specimens of many species in the family Achatinellidae.

Although Achatinella apexfulva does not have a common name, I call it the "yellow-tipped little agate snail" as a direct translation of its scientific name. The Achatinellidae in general are colorful and attractive. Sadly, most, including A. apexfulva, are now extinct.

When governments peer down the wishing well

kw: book reviews, nonfiction, esp, research, government programs

Beginning in the 1940's (so far as we know) several U.S. military and government agencies studied phenomena typically called ESP or psychic, and actually made use of "Remote Viewing" and "Map Dowsing", for example. Although most official connection with such "enhanced skills" ended in the 1990's, not all such efforts have ended, and an unknown amount of work has likely "gone dark".

The title of the book introduces the whole subject: Phenomena: The Secret History of the U.S. Government's Investigations into Extrasensory Perception and Psychokinesis by Annie Jacobsen. A few startling successes have been recorded, and were brought out by FOIA requests by the author:

• In 1972 Ingo Swann affected the operation of a "quark detector", really an ultra-sensitive superconductive quantum interference device (SQUID). As scientists and graduate students watched, a chart recorder that was just drawing a slowly shifting line suddenly drew a wiggly line. Swann asked if that was "a result." Asked to do it again, he looked thoughtful a moment, and it did it again. The lead scientist concluded that he had influenced the detector, which was located a level below them in a shielded chamber. I consider it equally likely that he influenced the chart recorder itself; this possibility is not mentioned.
• Beginning in 1973 several kinds of tests were performed with Uri Geller, the "spoon bender", who still entertains folks by bending spoons, tongs, or whatever, including items too strong to be bent sneakily, and by reading minds or putting thoughts into others' minds. He is credited with correctly reading the uppermost face of a die in a closed metal box, at least 8 times in a row. While living in Israel before this, he had been employed by Moshe Dayan as a map dowser, pointing out to Dayan the locations of archaeological sites and artifacts that had not yet been discovered.
• Also in 1973 Ingo Swann and an even more talented remote viewer, Pat Price, were asked to describe that they "saw" at a set of geographical coordinates, provided by another researcher. They were the coordinates of his mountain cabin. But the two of them, also describing the weather (easy today, using Accuweather.com, not so much 40+ years ago), described a large installation, partly underground, with communications and listening equipment and many technicians. Puzzled, the project leader drove to the site, and then around the side of the mountain he came upon a military installation the cabin's owner had not known was there. Swann and Price said, of course they had seen the cabin, but thought the nearby listening post was the real target.
• Skip a few: In 1981 Gary Langford, who was an active remote viewer, said, "A United States Pentagon official will be kidnapped by terrorists on the evening of 17 December 1981." On that date at 5:30 PM General James L. Dozier was kidnapped, and later killed. Remote viewers called in to locate him and check his welfare were certain he was alive for some time after his death, because, as it turned out, the killers kept his body on ice for months.

There are numerous other events that researchers called "8 martini results", because they'd need to go drink themselves blotto after witnessing such startling successes. These were military and CIA folks, not used to having their exceedingly rational world view challenged. But this last item above emphasizes a weakness of information provided by precognition and remote viewing. You can't do anything about it until it is too late. Had Gary Langford told the location of the kidnapping, perhaps something could have been done to prevent it. But he would likely then have also said it would be an attempted kidnapping that may or may not succeed.

A great many viewings by Angela Dellafiora, "the woman with the third eye", just drove the researchers wild. She was uncannily accurate. For many years the government officials had tried to separate these "extraordinary skills" from occultism. Ms Dellafiora made no bones about coming from a long line of women with "second sight", and she just wouldn't keep with protocol.

What are we to make of all this? The military, in particular, did their best to make remote viewing a trainable skill. All the evidence so far gathered points instead to what one skilled viewer said, "You have to be born. Not many folks will ever be able to do this."

Before going onto another tack altogether, I need to pick a nit or two with the author: On page 104 of the Little, Brown Large Print edition I read, she writes about the U.S. Embassy in Moscow that was constantly bombarded with microwaves in the 1950's and 1960's. She writes that the signal had "a power density between 2.5 and 4.0 Ghz". That describes a frequency, not power. This is nit 1. Also, it is never mentioned that years later this was found to be a bugging scheme, not an attempt to damage American consuls with microwaves: a decoration in a conference room was resonant at the frequency used, and had a thin metallic membrane on its outer surface. It would modulate and re-radiate the microwaves to a receiver outside the building. The Soviets were listening in on whatever went on in that room. Nit 2.

So, are there truly "paranormal" powers that are owned by a few "adepts"? More than half of us think so. This is a good opportunity to present a Christian perspective, or actually two of them. These are unlikely to be what you are thinking right now.

Firstly, some supposedly occult powers may actually be rare powers of the human soul. The premise of a book by Watchman Nee, The Latent Power of the Soul, is that great powers were to be found in Adam before the fall (whether "Adam" refers to one man or is a collective name for a number of humans who may have dwelt in Eden, makes no difference to the argument). Nee thought that Adam's managerial abilities alone might exceed our best executives by a million-fold or more. He also thought that some powers claimed by Yogis and other occult adepts might be soul power, and he considered that part of the curse of the fall was that most such soulish powers became imprisoned in the flesh; that this might be the reason Yogis and others must be such strict ascetics, so that they can subdue the body and release their soul power. Nee writes that this was God's doing, and without such restrictions, we would likely be too dangerous to one another, above and beyond the dangers we pose from physical means! Think of Darth Vader using "the Force" to kill at a distance.

Secondly, necromancy and other "information gathering" occult powers are typically performed with the help of a "familiar spirit." Shamans in many cultures have special spirits they call on. The Bible's point of view is that a familiar spirit is a demon, usually called an evil spirit in the Old Testament, and a demon in the New Testament. According to an analysis by G. H. Pember, there were men or manlike creatures before Adam, who remained loyal to the Archangel ("Lucifer") when that one rebelled against God. God's judgment on them was to be disembodied and sent to dwell in "the abyss", the deepest parts of the oceans. From time to time one or another will escape temporarily, and it wishes to re-enter a body. Susceptible persons, usually those already weakened in will by persistent and promiscuous sin, can thus be "possessed". I have seen a few startling things that convinced me that demons are real, they do possess certain persons, and that they can be expelled by a spiritual Christian. But on a different note, a witch or sorcerer is someone who has formed an allegiance with such a disembodied spirit, which does favors and proffers information in return for part-time possession of the person's body. Channeling is apparently something that takes place during such a temporary possession. Remote viewing and other information gathering activities may be carried out by demons so informing certain "sensitive" persons, for their own purposes. They can apparently, to a limited extent, foretell the future: perhaps Gary Langford was informed by a demon of a plot that was already planned by General Dozier's kidnappers. Pember wrote about these matters in the second part of his book Earth's Earliest Ages, in 1884. The first part of the book is about "the Gap", the eon's-long period between the first and second verses of Genesis.

Can we say for sure if any of these things are so? Not really, Isaiah sang, "Truly, You are a God who hides Himself" (45:15). God apparently actively prevents most demonic activity, preferring people to live earthly lives in which they will suffer enough anyway, from their own foolishness and from various unfortunate natural events. Such matters would be too time- and space-consuming to enter upon here.

The conclusion of Phenomena is that ESP sometimes happens, but is not very useful. There have been a few surprising successes, and far too many things that were shown to be accurate after the fact, but could not be of any help otherwise. And, of course, for every genuine adept who may exist, there are hundreds or thousands of charlatans and illusionists. A fascinating, if rather sad, book.

A snail family and a photo experiment

kw: species summaries, natural history, natural science, museums, research, photographs, digital darkroom

A few weeks ago I finished a project to clean up the data for all of the specimen lots of freshwater snails at the Delaware Museum of Natural History. We loaded almost 10,000 data records to the new database product, and linked them to the InvertEBase site (the link opens the Collections page; we are #3). Then I began working my way through the land snails (called terrestrial gastropods in most literature, and they include tree snails). The Curator and I decided to work taxonomic family by family, or in groups of related families, working with about 1,000-2,000 records at a time.

The two great groups of terrestrial gastropods are the Pulmonates (infraclass Pulmonata of class Gastropoda) and the Operculates (in class Caenogastropoda along with many freshwater and marine species). "Pulmonate" means they have a lung; "Operculate" means they have a small, separate shell with which they can block the aperture of their main shell when they pull inside, and this allows them to survive periods of dryness and also blocks most predators.

The majority of land snail families are Pulmonates, so we began with the family Ellobiidae and two related families, Carychiidae and Amphibolidae. Digging into current taxonomic research, I found that the family Carychiidae is now a subfamily of Ellobiidae, and is now named Carychiinae. I also found that, while a few species in family Amphibolidae are terrestrial, most are marine, and our collection contained only marine species. Nonetheless, having extracted the records, I proceeded with both families, dealing with 75 lots of Amphibolidae and 1,236 lots of Ellobiidae.

It is instructive to survey the family Ellobiidae, which tend to have a certain appearance no matter what environment they inhabit. Some genera are all terrestrial, some are all marine, a few genera are estuarine (adapted to brackish water), and others contain species found in various habitats.

We'll first look at Ellobium chinense (Pfeiffer, 1856). Lawrence Pfeiffer originally described the species under the name Auricula chinense, thus the parentheses around his citation, indicating the reclassification of the genus.

These are medium-sized, up to 3 cm long and 1.4 cm wide, and rather ovate or cigar-shaped. In the closeup below notice the small lump on the inner lip of the aperture. The apertures of nearly all species in this family are variously decorated, probably depending on the kinds of predators these snails encounter.

The genus Ellobium is primarily Asian, and this species occurs in Japan.

Here we have another strictly terrestrial species, Pythia pantherina (A. Adams, 1851). Though the genus of this species has been changed to Pythia, I don't have information what its earlier name was. (Scarabus) on the older label indicates a subgenus, now no longer used.

Shells of this genus have the most elaborate dentition in the aperture, which indicates they have more severe predation at the aperture, probably by birds. Such a wiggly aperture allows the soft-bodied snail to emerge and crawl about, but prohibits entry to all but the slenderest of bird beaks. Other predators have other ways in: see the shell at lower left in the closeup, with two tiny pinholes in its lower left area (I didn't notice them until I looked at the closeup). They are from a predatory drilling snail, which uses its abrasive radula (sort of like a tongue with tiny teeth) to scrape a hole through the shell. It then injects a nerve poison. The animal inside relaxes, and enough of it extrudes through the wiggly aperture that the predator can either dismember it in place or pull it out to be consumed.

The genus Pythia is found throughout the Indo-Pacific region, typically on mangrove roots above the high tide line, and a little further inland. These specimens, six of the eleven in this lot, are from the Sulu Archipelago of the Philippines.

The third species of interest is Auriculastra subula (Quoy & Gaimard, 1832); the genus was formerly Auricula. These are quite small, seldom exceeding 1 cm in length.

The closeup below shows a single tooth in the aperture on the inner lip, simlar to the Ellobium specimens above. This is an estuarine species, found on mangroves in tidal marshes. It is not fully marine and cannot tolerate ocean water for any length of time.

The genus Auriculastra occurs throughout the Indo-Pacific and South Pacific. These are from Fiji. They show more wear than the prior two species, indicating that they get roughed up in the sandy lagoons, probably during the frequent storms.

The fourth and final species is Ovatella algerica (Bourguignat, 1864), originally called Alexia algerica. These are very small, just a bit bigger than those called "minute", seldom exceeding 0.6 cm in length. Note, however that like the others they have the ovate/cigar shape characteristic of the family.

The closeup shows that they also have small teeth, in this case two of them, partially blocking the aperture. These are 8 of the 20 in this lot. The original label also shows a better example for future shell collectors than the other three: the town, the beach ("Quarry Beach" in Las Palmas), and the country, plus the month and year of collecting. Is lacks only the collector's name. I am not sure why an earlier version of the database placed these in Argentina, but I am glad it has been corrected ("Argentina" on the oldest label is in someone else's handwriting. The handwritten correction on the older DMNH label is from the 1990's.)

These species are found near-shore Europe and north Africa. Their habitats are fully marine to salt marsh. The Canary Islands are offshore from north-western Africa.

The photographic experiment I mention in the title is a matter of spacing for the sake of good focus. The typical way to photograph museum mollusk specimens is to arrange the specimens on black velvet, velveteen, or (as in 3 of the 4 cases above) on black felt, and then to arrange the labels and the scale indicator around them. But even the small shells of these Ovatella specimens have a significant thickness when being photographed close-up. One may either focus on the upper surface of one of the shells, or on the labels, with the consequence that the other will be a little out of focus. One way around that is to use a lens aperture of f/8 or f/11 for greater depth of field. I tried something different.

I cut a number of small pieces of corrugated cardboard, either 3/4" x 2" (2x5 cm) or 1/2" x 1.5" (1.3x3.5 cm). I put these under the labels to bring them up to a plane close to the tops of the shells. In the case of the Ellobium specimens above, it took three thicknesses of cardboard, and you can see the spacers under the smallest label in that photo and the first photo of the Pythia specimens. It worked very well! Everything I want to see is in good focus, using f/4 to f/5. I was also using a +2 closeup lens on my camera's 18-105 mm zoom lens.

With the camera back fixed at 24" (60 cm) above the table top, I used focal lengths of 36 mm and 105 mm. I used a spot focus just below the top of a central shell in each group for the autofocus to work with, and I am pleased with the results.

Each of the original images was cropped, and the color levels clipped to remove the grayness the camera allowed in the black background, and the gamma and saturation were adjusted so the colors in the image matched the colors of the shells. The images above are all re-sized to 1620x1080 pixels, so you can click on them to get images that fill most screens. I also used just a little bit of Unsharp Masking to emphasize the shell decorations, also to make the images look more "eyeball true". My Nikon camera under-sharpens its images, which I like. I usually prefer its usual, softer look, but when I want to sharpen back to "normal", UM is the most versatile way of doing so.

Finally, although felt is cheaper than velvet, the clean, smooth blackness of genuine velvet makes for much better final images, as can be seen by comparing the first two images with the other six.

The Great Pond Snail

kw: species summaries, natural history, natural science, museums, research, photographs

This tray contains all but four of the lots of Lymnaea stagnalis (Linnaeus, 1758) that are currently in the collection of the Delaware Museum of Natural History. It is called the Great Pond Snail because it is the largest freshwater snail found in Great Britain ("Great" in this case meaning "large"). L. stagnalis is the type species of the genus Lymnaea, which is the type genus of the family Lymnaeidae. You'll notice one box contains only a pink label. That indicates the lot is a Topotype; it was collected in the location where Linnaeus's first-described specimen (the Holotype) was collected. The museum keeps types in a special cabinet. I'll get into more about types on another occasion.

The Latin prefix lymn- is equivalent to limn-, which refers to a lake. As a matter of fact, I am a bit puzzled that the family is not named Limnaeidae and the genus Limnaeus (but see below). The species was first named by Linnaeus as Helix stagnalis. He placed nearly all the spiral-shaped gastropods he knew of in the genus Helix, for obvious reasons. Later workers broke up the genus into quite a number of new genera so as to group the species more appropriately. For a time, subgenera had been created to group the species, and in fact, Lamarck renamed this species Lymnaea (Lymnaea) stagnalis in 1799, while placing several other former Helix species into that subgenus; the subgenus name is in parentheses. Later genus-splitters removed the subgenus designation. In 1875, Sandberg tried to rename the genus Limneus, considering it a justified spelling correction. Nearly everyone else disagreed because of priority rules, and so Lymnaea it remains.

Members of the family Lymnaeidae are lake snails almost exclusively, and some are also found in slow-moving streams, such as in deltas. This species in particular favors very quiet, shallow waters, even stagnant waters if the oxygen content is not too low. Thus the species name stagnalis.

I chose to photograph two of the lots. This first, catalog #60565, was collected in a shallow part of the Niagara River, on the New York side. These are the largest specimens of this species at DMNH. I neglected to put the scale in, but the museum label is 1" x 3", so the largest specimen's height is about 2.3" or 57 mm. The largest recorded specimen just exceeded 60 mm.

These shells, being nearly translucent and very light in weight, practically broadcast their environment: very quiet water and an absence of shell-crunching predators. However, they are hosts to several parasites, and intermediate hosts to at least six different flukes, including one that can severely affect humans. Thus, these are well studied because of their medical and economic impact.

They are "ubiquitously holarctic", meaning they are found throughout the Northern Hemisphere, particularly at higher latitudes, though south of the permafrost line. They apparently hunker into the mud to over-winter in England, Scotland, across northern Europe including Russia, and across the northern U.S. and Canada.

The second lot shown, #119635, contains some of the smallest adult specimens in this collection. The longest is just over 0.8", or 21 mm. Although these were collected in 1926, this indicates that the river where they were found, in or near Detroit, Michigan, must have already been heavily polluted.

Note that both of these lots have subspecies designations on the collectors' labels; one was jugularis and the other, expensa. These are now deprecated; so far as I have determined, no subspecies of L. stagnalis are recognized at present.

The labels of the second lot also show its history, or most of it. Originally collected by L. F. Merrill, it came into the hands of Grace M. Seymour, and then G. M. MacCoy, who donated it to DMNH. Sometimes, collections are accompanied by letters and other documents that tell more of the story. I haven't dug into the library records for the MacCoy collection to see if there is more to the tale.

Shell collectors who are dedicated enough to identify and index and label their specimens are dubbed Shellers. By contrast, the designation Conchologist is reserved for those who also devote time to studying shells, and perhaps living mollusks, and professional Conchologists are called Malacologists. Mollusk enthusiasts and dealers Guido and Philippe Poppe have gathered information about more than 41,000 Shellers in their site Conchology Inc., from which they sell and trade shells, and curate a kind of online museum. It is one of a handful of online resources that I have found very useful to determine the full name of someone. Interestingly, however, none of these three Shellers is included. Neither is Esley Doremus, the donor of the lot from New York.

At least we have the initials for two of them and full names for the other two. In many cases I find a label that says nothing more than a species name, a location, and a surname followed by "leg." or "legit.", the usual Latin designations for a collector. The abbreviation "col." is also sometimes used, but "coll." usually means "from the collection of"; Shellers trade and buy shells so much that for many large collections, only a small percentage of the holdings were actually self-collected by the owner.

The 78 lots of this species held at DMNH allow researchers to study areal extent, presence through time at locations or in areas that were visited more than once, and changes in animal health. I occasionally find a note among the labels that specimens were collected from the bed of a dried-up pond, indicating at least local extinction. Rather poignant, that.