Dr. Rob Dillon, Coordinator

Tuesday, November 5, 2019

Isaac Lea Drives Me Nuts

Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023b)  Isaac Lea Drives Me Nuts.  Pp 25 – 33 in The Freshwater Gastropods of North America Volume 6, Yankees at The Gap, and Other EssaysFWGNA Project, Charleston, SC.

He was born the fifth son of an affluent Quaker merchant in the bustling port of Wilmington, DE, and sent to Philadelphia at age 15 to work in the importing and wholesaling business with his eldest brother.  In Philadelphia he struck up a friendship with Lardner Vanuxem (1792 - 1848) also the son of a prominent Quaker merchant, and the pair became interested in natural history together, focusing especially, at this early date, on rocks, minerals, and fossils.  In 1814 both Lea and Vanuxem joined a volunteer rifle company, and were expelled from the Religious Society of Friends wholesale, which was the way their community preferred to do business, in those days.

Isaac Lea (1792 - 1886) [1]
In 1815 Lea and Vanuxem were elected to membership in the Academy of Natural Sciences of Philadelphia, then in existence for three years.  Prominent among the founders of the Academy was, of course, Thomas Say (1787 - 1834), the Father of American Malacology.  The biographical similarities between Say and Lea are striking: both the sons of prominent Philadelphia-area businessmen, both kicked out of the Quakers for volunteering during the War of 1812, both autodidacts.

For this essay I am relying primarily on the scholarly 1885 biography and bibliography compiled by N. P. Scudder [1], with occasional reference to W. H. Dall [2].  And one of the more peculiar aspects of both references is the absence of any exploration of the relationship between Isaac Lea and Thomas Say. On page VIII Scudder recorded: “Mr. Lea remembers that Mr. Say founded his genus Alasmodonta on a single valve which he himself had picked up on the river shore at Chilicothe, Ohio, and which he carried from that place to Philadelphia in his saddle bags.”  And that is (almost) all we know about the relationship between these two giants of American malacology today.

Vanuxem went on to the Paris School of Mines, and from thence to a university professorship.  Lea published his first paper in the Journal of the ANSP in 1817, “An account of the minerals at present known to exist in the vicinity of Philadelphia.”  But he did not pursue an academic degree of any sort [3], marrying the daughter of a prominent publisher and shifting his business to that of his father-in-law.

Scudder attributes the origin of Lea’s malacological interests to the arrival in Philadelphia of two shipments of unionid shells - one from a brother in Cincinnati, the second from the 1825 expedition of Major Long.  And in 1827 Lea published his first malacological paper, “Description of six new species of the genus Unio.”

One cannot help but notice that two years previous, Thomas Say had quit Philadelphia and sailed down The Ohio to help found the utopian community at New Harmony.  Was the malacological awakening of Isaac Lea a coincidence?  Or was there room for just one malacologist in Philadelphia?  Thomas Say had served as the chief zoologist on Major Long’s expedition to the headwaters of the Mississippi, which means, ironically, that Say may have collected the unionid shells that Lea first described, just as Lea claims to have collected unionid shells first described by Say.  The relationships among the 19th-century American malacologists seem to have been a complex thing.

For whatever reason, the explosion of malacology that erupted from the pen of Isaac Lea would continue almost unbated for 50 years.  Ultimately, he published 279 articles, papers, monographs and books, describing as he did 1,842 species.  To wit:

Species described by Isaac Lea [1]. Click for larger.
Through the 1830s, Lea focused his efforts almost exclusively on this first love, the Unionid mussels.  His first big swing at our favorite organisms came in 1841, with the publication of his “New Fresh Water and Land Shells,” in which he described 57 species of Melania, including such notables as M. clavaeformis and M. ebenum [4].  This series (using variants of the same title) continued until 1848.  In the 1850s he seems to have been distracted once again by other taxa, but he came roaring back to the freshwater gastropods in the 1860s, describing scores of additional species and four new pleurocerid genera, including Goniobasis.

I have modified the adjective “unabated” with the adverb “almost” in the sentence two paragraphs above for two reasons: Lea’s extensive European tours of 1832 and 1853.  On his return from the 1832 trip: 
“to his great astonishment he found that advantage had been taken of his absence, which had prevented him from securing his share of the collection of Tertiary fossils of Alabama, made by Dr. Gates … and that the whole of the Philadelphia quota had been placed in the hands of Mr. Conrad, who was not one of the subscribers. Mr. Lea was not made acquainted with the fact until he saw the first numbers of Mr. Conrad's published descriptions.”
This, I infer, was the beginning of a lifelong feud between Lea and Timothy Abbott Conrad (1803 – 1877), the prominent Trenton-area paleontologist and malacologist, also an excommunicated Quaker [5], elected to membership of the ANSP in 1831.  The feud also seems to have involved Thomas Say.  Because when Lea returned from his second European tour in 1853 [6], again quoting Scudder: 
“He found that Mr. Conrad had published “A Synopsis of the family of Naiades of North America” in the early part of the year, which was full of errors both of date and facts.  These were all stated in Dr. Lea's "Rectification," published immediately on his return, in order to correct any false impressions they might have given. He likewise found that Mr. Say had also published a short list of the species, in which he differed much from Mr. Conrad, but he did not give Dr. Lea a single species.” 
By his death at the age of 94 Isaac Lea had become “the Nestor of American Naturalists [7].”  He was president of the ANSP from 1858 – 1863, and (indeed!) elected president of the AAAS in 1860, and apparently lionized in his day.  He cannot be judged otherwise in ours [8].  Had the noun “species” been defined by the community of systematic biologists active in the 19th century, which I don’t think it was, it would have been something like, “a type considered distinct by a competent taxonomist,” which Isaac Lea most certainly was.  I cannot find any evidence that he ever heard of Charles Darwin [9], much less integrated evolutionary thinking into his work, but I honestly don’t think the discipline of malacology met Darwin until well into the 20th century, and it would be unfair to expect otherwise.

Would it be fair to judge Lea through the eyes of a contemporary?  George W. Tryon Jr. (1838 - 1888) was prominent in the generation of malacologists who followed in Lea’s footsteps.  In 1866 Tryon founded the “Conchological Section” of the ANSP, which he directed until his untimely death [11].  And in 1873 Tryon published the first comprehensive monograph of the North American Pleuroceridae (“Strepomatidae”) [12], in the preface of which he thanked his “kind friend [13]” Dr. Isaac Lea “who not only gave me constant access to his noble collection, but on many occasions aided me by comparing specimens and elucidating knotty questions in synonymy.”

G.W. Tryon (1838 - 1888) [11]
So as of 1873, Tryon recognized 464 valid species of pleurocerids [15] in ten genera.  His monograph is a marvelous work of scholarship, to which I refer often, but I just do not have the patience this morning to go through all 435 pages and count all the synonyms under all those 464 species.  Let me select the typical genus Pleurocera, in which Tryon recognized 99 valid species [16].
Thumbing through the 89 monograph pages in which Tryon reviewed the 99 species [17] of Pleurocera that he considered valid as of 1873, I count 49 real synonyms, setting aside alternate spellings.  Those synonyms comprise 29 of Isaac Lea and 20 from eight other pleurocerid researchers combined [18].  So even Tryon, who was hosted by Lea in his collection and instructed by him personally in the finer points of synonymy, considered that his kind friend, seated in bearded eminence at the high table over his right shoulder [19], had screwed up 29 times in the genus Pleurocera alone.

And the problem is even worse than it looks.  Of the 99 Pleurocera species considered valid by George Tryon, 71 were described by Isaac Lea.  If Lea had 29 more rings than he had pegs to throw them on, one would expect that he would toss them on his own pegs 71/99 = 72% of the time, and on anybody else’s pegs the remaining 28% of the time.  But in fact, only 14/29 = 48% of Lea’s synonyms were self-synonyms according to Tryon, while 15 of Lea’s synonyms were cast on the (just 28) species previously described by somebody else.

Did Isaac Lea willfully ignore the work of his colleagues?  Or was he just too busy talking to listen to anybody else?  Either way, this drives me nuts.

Well, although Calvin Goodrich (1874 - 1954) did not monograph the Pleuroceridae in any formal sense [20], through the 1930s and 1940s he effectively pared the American list of pleurocerid species and subspecies down to 199, of which a mere 93 were Isaac Lea’s.  Those 199 were sanctified by Burch [21] into holy scripture.  How many of the 93/199 = 47% of all the canonical species of North American pleurocerids described by Isaac Lea might be valid, by modern biological criteria?  We’ve nibbled around that question on several occasions in recent years [22].  We’ll take another nip at it in the next couple essays.


[1] Scudder, N. P. (1885)  Bibliographies of American naturalists – II. The published writings of Isaac Lea, LL.D.  Bull. US National Museum 23: 1 – 278.

[2] Dall, W. H. (1888)  Some American Conchologists.  Proc. Biol. Soc. Washington 4: 95 – 134.

[3] One usually sees him referred to as “Dr.” Isaac Lea.  Harvard College bestowed an honorary LL.D. on Lea in 1852.

[4] Lea. I. (1841)  New fresh water and land shells.  Proc. Amer. Philos. Soc. 2: 11 – 15.

[5] Conrad was stricken from the roll of The Religious Society of Friends in the same year he was elected to the ANSP, “because of a preference for walking afield to attending religious services.”  The Quakers founded the middle colonies and dominated them, in every way imaginable, for over a hundred years.  But today, even in the Philadelphia metro area, only approximately 1% of adults identify with the Religious Society of Friends, according to the recent Pew survey.  That’s approximately the same proportion as the Hindus.

[6]  I think the biographer Scudder may be confused here.  Conrad’s “Monography of the Family Unionidae” was published between 1835 and 1847.  And Say died in 1834.  So I think all this unionid sturm und drang kicked off after Lea’s first (1832) European tour, rather than after his second tour of 1853. Ironically, Scudder seems to be fussing about Lea fussing about Conrad screwing up dates, as Scudder is screwing up dates.  But at this point, to quote Bill Murray, “It just doesn’t matter.”

[7] This sobriquet comes from Dall [2].  And I confess that I had to google it, too.  In both The Iliad and The Odyssey, Nestor was the wise and ancient king to whom younger warriors, such as Agamemnon and Achilles, turned for advice.  The effect of Nestor’s wisdom was diluted, however, by his boastfulness.  His advice was always prefaced by lengthy accounts of his own heroic actions under similar circumstances in the distant past.

[8] One of the most unpleasant aspects of human nature is that we all set ourselves at the high bench to judge our fellow man.  And historic figures we judge by our own entirely personal, inevitably modern criteria.  So for example, in recent years we seem to have cast Thomas Jefferson into the outer darkness, convicted of the high crime of slavery, his merits as a patriot forgotten.  In the days of my youth, Jefferson was a demigod.  But turning back two pages, if you’d asked contemporaries like George Washington or John Adams, they couldn’t stand the jerk.

[9] Scudder chronicles Lea’s European tours of 1832 and 1853 in breathless detail [10], including everybody Lea met, and didn’t meet, and what everybody said to him, and what he said back.  In England he did meet Faraday, Dalton, and Lyell, among many others, but not Darwin.  William Hooker yes, his son Joseph Dalton Hooker no.  Sedgwick yes, Huxley no.

[10] Here’s an example: “Calling at the Museum of Economic Geology, Dr. Lea found Sir Henry De la Beche busily engaged. He expressed much pleasure at seeing him again. While conversing with him a very old gentleman came in whom he introduced as Mr. Weaver. He was entirely deaf, and Dr. Lea had to write his part of the dialogue.  He was ninety-one years old, was perfectly erect, and had a remarkably fine face. Dr. Lea was very much pleased to see him, for he was of the old school of science, and was a fellow-student with Humboldt. He was kind enough to say that he had heard in the hall that Dr. Lea was in the private room with Sir Henry, and he could not refrain from coming to shake hands with one who had done so much for American science.”  Don’t you wish that Scudder had chronicled anything like that detail for the relationship between Isaac Lea and Thomas Say?

[11] Ruschenberger, W.S.W. (1888) A biographical notice of George W. Tryon, Jr. Proceedings of the Academy of Natural Sciences of Philadelphia 40: 399 – 418.

[12] Tryon, G. W. (1873)  Land and Freshwater shells of North America Part IV, Strepomatidae.  Smithsonian Miscellaneous Collections 253: 1 - 435.

[13] Tryon was of Lutheran heritage, converted [14] to the Quakers in 1853, and then to the Unitarians in 1876, according to Ruschenberger [11].  So, the noun “friend” may have carried special meaning between Tryon and Lea in 1873.

[14] Tryon would have been 23 years old when war broke out between the states.  So, his transitory affiliation with the Quaker faith is not difficult to understand.

[15]  The number 464 was given by Tryon in his introduction.  The actual number of pleurocerid species Tryon ultimately recognized in his monograph seems to have been more, but I don’t have patience to hand-count.

[16] Tryon quoted 84 species of Pleurocera in his introduction, but by actual count there are 99.

[17] The 99 species included Pleurocera leaii Tryon, 1861.

[18] Anthony = 9, Menke = 3, Say = 2, Reeve = 2, one each for Brot, Hald, Adams, and Wood/Ward.

[19]  Yes, Isaac Lea, 46 years Tryon’s senior, predeceased him by just two years.  Dall [2] termed the first period of American malacology the “Sayian” and the second period the “Gouldian,” with only Isaac Lea surviving to link the two.

[20]  To learn more about Calvin Goodrich, I would be most gratified if you would purchase FWGNA Volume 3 [html] and read the first ten pages.  Or you could take the easy way out:
  • The Legacy of Calvin Goodrich [23Jan07]
[21] This is a difficult work to cite.  J. B. Burch's North American Freshwater Snails was published in three different ways.  It was initially commissioned as an identification manual by the US EPA and published by the agency in 1982.  It was also serially published in the journal Walkerana (1980, 1982, 1988) and finally as stand-alone volume in 1989 (Malacological Publications, Hamburg, MI).

[22]  Lea hit clavaeformis but whiffed on acutocarinata and ebenum in 1841:
  • Goodrichian taxon shift [20Feb07]
  • CPP Diary: What is Pleurocera ebenum? [3Oct19]
He got a solid hit in 1862:
  • One Goodrich Missed: the skinny simplex of Maryville is Pleurocera gabbiana [14Nov16]
But went 0-for-4 in 1863:
  • CPP Diary: Yankees at The Gap [4Aug19]