Monday, December 14, 2015

Micro to Macro, Nature to Art

Scale.  It’s an ongoing effort to strike a proper or, perhaps, comfortable balance.  Walk along 10th Street toward the Smithsonian’s National Museum of Natural History and lurking on either side are the massive, stolid buildings of the U.S. Justice Department and the Internal Revenue Service.  The message about one’s insignificance is clear.  Reach Constitution Avenue, a broad, multi-laned river of traffic, extending to the right and left.  Cross the avenue to the museum.  Before the entrance, two small gardens sit island-like, bordered by stone.  These restore some degree of welcome equilibrium.  Even the trees, ginkgo (Ginkgo biloba) and European larch (Larix decidua), in these garden islands are modest.

Curiously, the recent, sudden appearance in the gardens of two very much larger-than-life sculptured models of microscopic foraminifera shells has not upset that equilibrium.  These stone models, each roughly two to three feet long, represent two extant species of these tiny (typically less than ½ millimeter in length) single-celled marine protists.  Most species create multi-chambered shells, adding new chambers as they outgrow the array of earlier ones.  The species modeled here are Buzasina ringens from the South China Sea (the first image below), and Ishamella apertura from Florida (the second and third images showing a side of the model and the shell’s aperture).

I don’t know the full story behind these foraminifera sculpture; a couple of inquiries of the NMNH have yielded nothing.

The fashioning of three-dimensional, enlarged models is not unique to foraminifera among students of microorganisms.  Indeed, leave the gardens and wander into the Museum’s Sant Ocean Hall.  Once there, admire a beautiful model of a dinoflagellate (Cyratocorys horrida), enlarged 1,000 times from a 0.15 mm actual specimen:

Or, to push the issue of scale even more, wonder at the explosive action frozen in the model of a radiolarian (Didimocyrtis tetrathalamus) enlarged 3,400 times from a 0.06 mm specimen:

Though there is a long history of the creation of models of very small organisms, I sense something unique about the modelling of foraminifera shells.  For a variety of reasons, which I will consider (i.e., fumble with) in a moment, foraminifera shells seem to cry out to be rendered in large scale models.

Engaged in creating the first systemic classification of foraminifera, the Frenchman Alcide d’Orbigny issued, in 1823, the initial of four installments of plaster models of foraminifera.  These models were based on original limestone sculptures that he’d carved.  Each installment contained 25 models; those of extinct species were colored, recent species were white.  Each model showed a foraminifera specimen; many were between 1 and 2 inches long.  Most amazing, the first installments of d’Orbigny’s models were sold to subscribers three years before they received his text describing and categorizing foraminifera genera and species.

In that publication, d’Orbigny placed the foraminifera into their own order with 5 families, 64 genera, and 544 species.  At the time, he mistakenly believed foraminifera were cephalopods, part of the mollusc phylum.  While only a few plates accompanied the text, illustrating just 31 species, d’Orbigny had a much more extensive array of plates that were intended for publication, but his foraminifera work was seriously disrupted in 1826 when the 24-year-old naturalist embarked on an eight-year journey to South America (described in a previous post).

Pictured below are several examples of d’Orbigny’s plaster models.  The California Academy of Sciences has posted many images of these models on Flickr and generously allowed them to be used under the Creative Commons Attribution Noncommercial-NoDerivs 2.0 Generic license.  The brightness and contrast on each image has been adjusted to enhance the details of each model.  There are three images of each model showing two sides and an edge.

Anomalina elegans

 Globigerina bulloides

Gyroidina orbicularis

Hansenisca soldanii (originally named Gyroidina soldanii by d'Orbigny)

Siderolina laevigator

(The preceding discussion of d’Orbigny’s work is based on various sources, including the following:  d’Orbigny’s 1826 publication titled Tableau Méthodique de la Classe des Céphalopodes, Annales des Sciences Naturelles, Series 1, Volume 7, 1826; Jere H. Lipps, The Unpublished Plates of Foraminifera by Alcide d’Orbigny – the Dawn of Micropaleontology, Palaeontologia Electronica, Volume 9, Issue 2, 2006; Edward Heron-Allen, Presidential Address, 1916-17:  Alcide d’Orbigny, his Life and his Work, Journal of the Royal Microscopical Society, February, 1917; Paul D. Taylor, Picture Quiz:  Alcide d’Orbigny (1802 – 1857), The Linnean, Volume 18, Number 2, 2002; C. Giles Miller, A Brief History of Modelling Foraminifera:  From d’Orbigny to Zheng Shouyi, in Landmarks in Foraminiferal Micropalaeontology:  History and Development, A.J. Bowden, et al., editors, The Micropalaeontology Society, 2013.)

Giles Miller offers an overview of some of the story of foraminifera models in his excellent piece, A Brief History of Modelling Foraminifera (cited above with a link).  Miller, Curator of Micropalaeontology at the Natural History Museum, London, describes numerous modelling efforts, some of which involved mass production (I guess that's what it would be called) like d’Orbigny’s models, while others consisted of models created by a single scientist for his own use.  He notes that “other sets of foraminiferal models not covered in this paper almost certainly exist . . . .”  (p. 337)  Miller describes nearly a dozen sets of models or individual models created at various points in the last couple of centuries.  Among them are those marketed in roughly the middle of the 19th century by the Czech Václav Frič whose models reflected the scientific thinking of the Austrian August von Reuss; the single set of glass and plaster models made by Frederick Gordon Pearcey, a member of the famous H.M.S. Challenger expedition of the 1870s (subject of a previous post); the plaster models created by someone named Chaffer and marketed in the early 1900s in England; sets of 50 “different forms” of foraminifera that were created by geologist Brooks F. Ellis and one his students, Julian Kane, and sold in the U.S. and Europe in the early 1950s; and the 4 sets of 10 models each currently sold by Kane Scientific.

One modelling effort merits separate treatment.  Expanding from her creation of hand-sized models, Chinese scientist Zheng Shouyi spearheaded an effort to create a park in Zhongshan, China, which opened in 2009 and features 114 huge marble, granite, and sandstone sculptures of foraminifera.  Some dwarf the people standing beside them, providing a sense of their scale.  Pictures of the park appear in Giles Miller’s article cited earlier and in Karen Larkins’ piece titled Evolution World Tour:  Foraminifera Sculpture Park, China (Smithsonian Magazine, January, 2012).

Why this strong impulse to fashion foraminifera models?  Based on my own work with foraminifera fossil shells, I will hazard that, at some fundamental level, foraminifera naturally lend themselves to modelling, partly because they come in such a breathtaking array of different shapes (reflecting the myriad ways the chambers in the shells are arranged, as suggested by the d’Orbigny models shown earlier), and partly because distinguishing among species often demands consideration of specimens in three dimensions.  To make key distinctions, one often has to examine, under magnification, all facets of a shell from all angles, and be able to relate those facets, one to another.  Drawings and photographs, even (or particularly) SEM (scanning electron microscope) images, are not always up to the task.

As delineated in Miller’s piece, modelling of these protists has often arisen from an educational impulse, within both academic and museum settings.  Clearly, that instruction can serve a very specific agenda.  For example, d’Orbigny saw the models as offering a critical way to demonstrate and promote the classification system he was propounding for foraminifera.  As he explained, “With a view to giving greater publicity to the work I had undertaken, and with the object of making it available to everybody without entailing the necessity of observing the numerous genera of Foraminifera under the Microscope, I have had the idea of sculpting a shell of each genus and each sub-genus of this order . . .”  (As quoted in Heron-Allen, cited earlier, p. 14.)

As d’Orbigny noted, a means of magnification is a necessity for observing these shells, potentially limiting their accessibility.  Though he prepared drawings of many of the shells covered in his Tableau (of which only a few found their way into the publication), he evidently believed these were insufficient for the task at hand.  Hence, the models.

I was amused at Heron-Allen’s comment that some of his own late 19th and early 20th century contemporaries who studied foraminifera looked askance at such models because, he reasoned, they failed to consider that d’Orbigny did not have at his disposal “microphotography” which Heron-Allen posited had “revolutionize[d] the study of microscopic life.”  (p. 14)  Heron-Allen might be surprised at the continued production of models up to the present, even as improvements in the photographic imaging of microscopic specimens have continued apace.

Indeed, in terms of developing technology, a marriage of 3-D printing and foraminifera shells seems ideal for foraminifera.  Micropaleontologist Ellen Thomas is part of an NSF-funded effort promoting that marriage, and her teaching now includes models of foraminifera and ostracodes generated by 3-D printers through a process that begins with CT scans of specimens to create 3-D “virtual fossils.”  Thomas notes, “With this, the fossil becomes a real object.  It becomes tactile and tangible and becomes a real teaching tool.”  (Olivia Drake, Thomas Uses CT Scans, Computer-Aided Visualization to Study and Teach Microfossils, News@Wesleyan, Wesleyan University, February 10, 2015.)  Yes, very tactile and tangible as shown below in a picture of one of her 3-D printed models of a Cibicidoides wuellerstorfi.

(This picture, which appears in the article just cited, is reproduced here with the kind permission of Olivia Drake at Wesleyan University.)

A micropaleontologist who works with other kinds of microfossils suggested to me that perhaps there’s a bit of a “founder effect” at work with foraminifera modelling.  As already noted, d’Orbigny, who laid the groundwork for the study and classification of foraminifera, started with models before text and drawings.  Perhaps that has biased subsequent workers with these shells.  It’s a thought.

One additional and, perhaps, key reason for the continuing creation of these models is how beautiful foraminifera shells are.  As the sculptures in the gardens before the National Museum of Natural History attest, scale up these microorganisms into hand-sized or larger objects and we cross from works of nature to works of art.
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