Thursday, February 28, 2013

The Adventure of the Unobservant and Unseeing Collector and the Lion's Mane

You see, but you do not observe.  The distinction is clear.

~ Sherlock Holmes to Dr. Watson in the story
A Scandal in Bohemia

Fossil hunting is often a series of small mysteries and bits of deduction.  Apparently, for me, it may also be periods of failing to see or observe.

In the middle of February, I went down to the Chesapeake Bay in search of microfossils and a bit of winter.  I hoped I would find a blast of frosty air sweeping off the waters.  I’d had enough of the false winter that had settled on my part of the mid-Atlantic region with little snow and temperatures that were much too bearable.  The flocks of robins that stayed in my neighborhood these past few months have forsaken their role as the heralds of spring, they’re becoming just another of the usual local avian denizens during the winter.

I prowled the beach for just a couple of hours.  I thought I’d failed to find any real trace of winter, but I successfully discovered some middle Miocene fossil bivalves that had come out of the Calvert Cliffs with both valves intact and filled with matrix.  Such sandy clay is often rich in foraminifera and ostracode shells (very roughly 13 to 15 million years old).  Articulated shells of the mollusks Chesapecten and Glycymeris were bagged for the trip home.

Then I saw two long, narrow pieces of fossil bone lying neatly atop a block of gray clayey matrix at the edge of a large expanse of slump that had come off the cliff.  A mystery.  The beach was deserted and had been all morning, so I deduced that these slivers of bone had been placed here in the past day or so by someone who had been digging through the slump.  Had he or she considered them to be just random shards of whale or dolphin bone?  Had they been set out on this piece of matrix as a gift to the next collector with low enough standards to add them to his collection?  Or, better yet, as an offering to the fossil gods?

Actually, I have come to think that the unknown hunter who preceded me hadn’t closely observed these bone fragments which, it turns out, are pieces of jaw neatly lined with empty, relatively uniform tooth sockets.

I couldn’t resist.  I pocketed them (low standards?).  As far as I'm concerned, jaw sections with extant tooth sockets are relatively scarce along this part of the Bay because the bone tends to break along the socket line which marks a weakness in the fossil.  These fossils came from one or two Miocene homodonts (animals with homogeneous teeth), most likely dolphins.  To provide some context to my fossils (not necessarily to suggest an identity for the animal from which they came), here is a picture I took of the skeleton of Xiphiacetus sp., a middle Miocene dolphin apparently from the Calvert Cliffs, on display at the Smithsonian’s National Museum of Natural History.  I’ve attached a close-up of a portion of the jaw to the image of the full skeleton.

 Later that morning, in sand on the water’s edge, I came upon a worn fossil vertebra, also possibly from a dolphin.  This is evidently from a juvenile animal because I observed a distinctive pattern on the end (seen in the picture below) which is the signal that the epiphysis or growth plate is missing, that it never fused with the vertebra.  Such fusion occurs when animals reach maturity.  The vertebra is also missing most of its processes.

I think that it was only as I turned to work my way back up the beach, that I really paid attention to some patches of something faintly tinted red and pink drifting along in the wash.

Jellyfish!  Those harbingers of the dog days of summer along this coast, those scourges of bathers, those floating gelatinous globs of stingers and stomachs.

What, in heaven, were they doing here on the Bay in the middle of February?  Another signal of a climate gone haywire, seasons knocked out of whack?  That was certainly my conclusion.  I was fully convinced that I’d never encountered them in my past mid-winter treks to the Bay.  The jellies on the Bay in the winter joined the lingering robins as my new stories of the effects of climate change.  The jellyfish pictured below is perhaps 5 inches across.  

 But, in all likelihood, I was wrong about this.  In past years, I probably not only didn’t observe, I didn’t see all that was around me as I wandered these beaches in winter.

As Holmes explains to Watson in A Scandal in Bohemia, the foundation of his deductions is seeing and observing.  To illustrate the “clear distinction” between the two, Holmes continues, “For example, you have frequently seen the steps which lead up from the hall to this room.”  Watson says that, of course, he has.

            “Then how many are there?”

            “How many?  I don’t know.”

“Quite so!  You have not observed.  And yet you have seen.  That is just my point.  Now, I know that there are seventeen steps, because I have both seen and observed.”

I don’t know what Holmes would make of a fossil hunter out on the beach who fails not only to observe, but apparently even fails to see.  Certainly not ask him to write up his cases as Holmes asks Watson immediately after telling him he is unobservant.

Upon returning home, I turned to Life in the Chesapeake Bay by Alice and Robert Lippson (3rd edition, 2006) and looked up jellyfish.  Not unexpectedly, topping the list was the “infamous stinging sea nettle,” Chrysaora quinquecirrha, which often plagues Bay beaches during the summer, but disappears in the fall after spawning, its fertilized eggs having developed into minute larvae which drift to the bottom, attach themselves, and develop into polyps.  These wait for the temperatures of spring to release the medusae that will then grow into the nettle form we know and love.

I was quite shocked to see that number two on this list was Cyanea capillata, known as lion’s mane or winter jellyfish.  These are the Bay’s jellyfish during the winter and they’re not just a marginal thing either.  According to the Lippsons, the lion’s mane jellyfish can be “as abundant in the Bay as sea nettles, but it occurs only during winter and spring months.”

It troubled me initially that pictures of lion’s mane jellyfish that appear on the web generally bear only a passing resemblance to the organisms I spotted on the beach a couple of week ago.  They differ often as to color (somewhat) and size (markedly).  So I consulted a professional marine naturalist who, based on the photo I provided, confirmed that what I’d encountered was indeed Cyanea capillata.  The Lippsons do note that the lion’s mane jellies can come in various sizes, and that further north in the Atlantic, they are larger, apparently living up to their names by sporting extremely long and dense tentacles, and becoming more like the model of a lion’s mane jellyfish which graces (terrorizes) the Smithsonian Natural History Museum’s Sant Ocean Hall (seen below in my picture).

According to the National Geographic, the lion’s mane jellyfish can reach a diameter of some 6.6 feet across with tentacles stretching out more than 49 feet.

I have to assume (with some reservation) that all of these past winters, the lion’s mane jellies have been decorating the beaches but they’ve never registered in my mind – apparently they were unobserved and unseen, and I was unobservant and unseeing.

This isn’t quite like stairs.  Unless he is singularly disconnected from reality, Watson couldn’t have replied to Holmes, “I assume there are stairs up to these rooms because I manage every day to get from the ground floor up to here.  I just don’t ever remember seeing them, so clearly I don’t have any idea how many there are.”

Have I been so disconnected?  Probably, but, I still wonder if perhaps this winter really is different.

Failure of sight, observation, and, indeed, memory.

It is appropriate at this juncture to turn to another Holmes mystery, one late in the canon, The Adventure of the Lion’s Mane.

This is only one of two stories narrated by the great detective himself.  He does a rather poor job of it, while revealing that, as he has aged, his memory has begun to fail.  The mystery is a singularly weak one, spotted with half-hearted red herrings that fail to suggest plausible alternatives to what has clearly happened.  (Belated spoiler alert:  Oh, yeah, I guess I’ve already given away the solution to this mystery.)

Holmes, now retired to a house in Sussex with a view of the Channel, solves the murder of Fitzroy McPherson, science instructor at a nearby educational institution.  One morning, McPherson, who despite a heart condition is a vigorous swimmer, staggers up the path from the beach and collapses in sight of Holmes.  On the verge of death, McPherson summons the strength to speak

. . . two or three words with an eager air of warning.  They were slurred and indistinct, but to my ear the last of them, which burst in a shriek from his lips, were ‘the Lion’s Mane.’  It was utterly irrelevant and unintelligible, and yet I could twist the sound into no other sense.  Then he half raised himself from the ground, threw his arms into the air, and fell forward on his side.  He was dead.

Oh, yes, “utterly irrelevant and unintelligible.”  (“Pay no attention to that man behind the curtain.”)

That his body is covered with welts, as though he has been whipped, only serves to deepen the mystery (hmmm).  To stir the pot a bit, Conan Doyle drops in red herrings and clueless police:  McPherson’s dry beach towel; a fellow teacher at the school who seems to hate everyone and who has had a falling out with McPherson; the local constabulary which is, as usual, utterly befuddled; some love notes between the dead man and a woman in the nearby village; and the woman’s father and brother who seem totally capable of murder over her affair with McPherson.

As the story progresses and Holmes eliminates all of the prime suspects, he struggles with the sense that something vital to the mystery lies buried somewhere in his memory.  He asserts that his mind holds a “vast store of out-of-the-way knowledge without scientific system, but very available for the needs of my work.”  Well, perhaps not so available, because he also admits that his mind’s “like a crowded box-room with packets of all sorts stowed away therein – so many that I may well have but a vague perception of what was there.”

So much for seeing and observing.  This is the Trivial Pursuit method of crime detection.  Of course, the missing little fact comes to Holmes, sending him off in a desperate search of his library for a particular volume.  With that nature book finally in hand, he solves the mystery and the monstrous, villainous jellyfish, found in a pool along the beach, is summarily dispatched.

Certainly not an adventure about seeing and observing.  For some reason, I don’t feel so bad about missing (if I did) the Cyanea capillata all these years.

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