Thomas Jefferson Papers

Memoir on the Megalonyx, [10 February 1797]

Memoir on the Megalonyx

[10 Feb. 1797]

To the American Philosophical society.1

In a letter of July 3. I informed our late most worthy President that some bones of a very large animal of the clawed-kind2 º had been recently discovered within this state, and promised a communication on the subject as soon as we could recover what were still recoverable of them.   It is well known that the substratum of the country beyond the Blue ridge is a lime-stone, abounding with large caverns, the earthy floors of which are highly impregnated with nitre; and that the inhabitants are in the habit of extracting the nitre from them. In digging the floor of one of these caves, belonging to Frederic Gromer5 in the county of Greenbriar, the labourers, at the depth of 2. or 3. feet came to some bones, the size and form of which bespoke an animal unknown to them. The nitrous impregnation of the earth had served to preserve them till such a degree of petrification was brought on as had secured them from further decay.6 The importance of the discovery was not known to those who made it. Yet it excited conversation in the neighborhood, and led persons7 of vague curiosity to seek and take away the bones. It was fortunate for science that one of it’s zealous and well informed friends, Colo. John Stewart, of that neighborhood, heard of the discovery, and, sensible from their description that they were of an animal not known, took measures without delay for saving those which still remained. He was kind enough to inform me of the incident, and to forward me the bones from time to time as they were recovered. To these I was enabled accidentally to add some others by the kindness of a Mr. Hopkins of New York, who had visited the cave. These bones are 1. a small fragment of the femur or thigh bone, being in fact only it’s lower extremity, separated from the main bone at it’s epiphysis,8 so as to give us only the two condyles. But these are nearly entire.

2. a Radius, perfect.9

3. an Ulna or fore-arm, perfect, except that it is broke in two.

4. three claws, and half a dozen other bones of the foot; but whether of a fore or hinder foot is not evident.

About a foot in length of the residue of the femur was found. It was split thro’ the middle, and in that state was used as a support for one of the saltpetre vats. This piece was afterwards lost; but it’s measures had been first taken as will be stated hereafter.

These bones only enable us to class the animal with the Unguiculated Quadrupeds,10 and, of these, the lion being nearest to him in size, we will compare him with that animal of whose anatomy Monsr. Daubenton has furnished very accurate measures in his tables at the end of Buffon’s natural history of the lion. These measures were taken as he* informs us from ‘a large lion of Africa,’ in which quarter the largest are said to be produced. I shall select from his measures only those where we have the corresponding bones, converting them into our own inch and it’s fractions, that the comparison may be more obvious: and to avoid the embarrasment of designating our animal always by circumlocution and description, I will venture to refer to him by the name of the Great-claw, or Megalonyx, to which he seems sufficiently entitled by the distinguished size of that member.

Megalonyx Lion
Inches Inches
length of the Ulna11 or forearm 20.1 13.7
height of the Olecranum  3.5  1.85
breadth of the Ulna from the point of the Coronoide apophysis to the extremity of the Olecranum  9.55
breadth of the Ulna at it’s middle  3.8
thickness at the same place  1.14
circumference at the same place  6.7
length of the Radius12 17.75 12.37
breadth of the radius at it’s head13  2.65  1.38
circumference at it’s middle14  7.4  3.62
breadth at it’s lower extremity15  4.05  1.18
diameter of the lower extremity of the femur, to wit, at the base of the two condyles  4.2  2.65
transverse diameter of the larger condyle at it’s base  3.
circumference of both condyles at their base16 11.65
diameter of the Middle of the femur17  4.25  1.15
hollow of the femur at the same place18  1.25
thickness of the bone surrounding the hollow19  1.5
length of the longest claw  7.5  1.41
length of the 2d. phalanx of the same  3.2  1.41
The largest of the bones of the foot20 in my possession
it’s greatest diameter, or breadth at the joint  2.45
it’s smallest diameter, or thickness at the same place  2.28
it’s circumference at the same place  7.1
it’s circumference at the middle  5.3
of the longest toe Middle sized toe Shortest toe
2d. phalanx, it’s length  3.2  2.95
greatest diameter at it’s head or upper joint  1.84  2.05
smallest diameter at the same place  1.4  1.54
circumference at the same place  5.25  5.8
3d. phalanx, it’s length *7.5 5.9  3.5
greatest diameter at it’s head or upper joint  2.7  2.  1.45
smallest diameter at the same place   .95   .9   .55
circumference at the same place  6.45  4.8

Were we to estimate the size of our animal by a comparison with that of the lion on the principle of ex pede Herculem, by taking the longest claw of each as the module of their measure, it would give us a being out of the limits of nature. It is fortunate therefore that we have some of the larger bones of the limbs which may furnish a more certain estimate of his stature. Let us suppose then23 that his dimensions of height, length and thickness, and of the principal members composing these, were of the same proportions with those of the lion. In the table of M. Daubenton, an Ulna of 13.78 inches belonged to a lion 42 1/2 inches high over the shoulders: then an Ulna of 20.1 inches bespeaks a Megalonyx of 5 f.—1.75 I. height.24 And as Animals who have the same proportions of height, length and thickness, have their bulk or weight proportioned to the * cubes of any one of their dimensions, the cube of 42.5 I. is to 262. ℔ the height and weight of M. Daubenton’s lion, as the cube of 61.75 inches to 803. ℔ the height and weight of the Megalonyx: which would prove him a little more than three times the size of the lion. I suppose that we should be safe in considering, on the authority of M. Daubenton, his lion as a large one. But let it pass as one only of the ordinary size; and that the Megalonyx whose bones happen to have been found was also of the ordinary size. It does appear that there was dissected for the academy of sciences at Paris a lion of 4 f.—9 3/8I. height. This individual would weigh 644. ℔ and would be in his species what a man of 8. feet height would be in ours. Such men have existed. A Megalonyx equally monstrous would be 7. feet high, and would weigh 2000. ℔. But the ordinary race, and not the monsters of it, are the object of our present enquiry.

I have used the height alone of this animal to deduce his bulk, on the supposition that he might have been25 formed in the proportions of the lion. But these were not his proportions. He was much thicker than the lion in proportion to his height, in his limbs certainly, and probably therefore in his body. The diameter of his radius at it’s upper end is near twice as great as that of the lion, and at it’s lower end more than thrice as great, which gives a mean proportion of 2 1/2 for 1.26 The femur of the lion was less than 1 1/4 I. diameter. That of the Megalonyx is 4 1/4 I. which is more than three for one.27 And as bodies of the same length and substance have their weights proportioned to the squares of their diameters, this excess of caliber compounded with the height would greatly aggravate the bulk of this animal. But when our subject has already carried us beyond the limits of nature hitherto known, it is safest to stop at the most moderate conclusions, and not to follow appearances through all the conjectures they would furnish, but leave these to be corroborated, or corrected by future discoveries. Let us only say then, what we may safely say, that he was more than three times as large as the lion: that he stood as preeminently at the head of the column of clawed animals28 as the Mammoth stood29 [at that of the elephant, rhinoceros, and hippopotamus: and that he may have been as formidable an antagonist to the mammoth as the lion to the elephant].

A difficult question now presents itself. What is become of the Greatclaw? Some light may be thrown on this by asking another question. Do the wild animals of the first magnitude in any instance fix their dwellings in a thickly inhabited country? Such I mean as the Elephant, the Rhinoceros, the lion, the tyger?30 As far as my reading and recollection serve me, I think they do not: but I hazard the opinion doubtingly because it is not the result of full31 enquiry. Africa is chiefly inhabited along the margin of it’s seas and rivers. The interior desart is the domain of the Elephant, the Rhinoceros, the lion, the tyger. Such individuals as have their haunts nearest the inhabited frontier, enter it occasionally and commit depredations when pressed by hunger: but the mass of their nation (if I may use the term) never approach the habitation of man, nor are within reach of it.32 When our ancestors arrived here, the Indian population below the falls of the rivers was about the twentieth part of what it now is. In this state of things an animal resembling the lion33 seems to have been known even in the lower country. Most of the accounts given by the earlier adventurers to this part of America, make a lion one of the animals of our forests. Sr. John Hawkins mentions this in 1564. º Thomas Harriot, a man of learning and of distinguished candor, who resided in Virginia in 1587. does the same. So also does Bullock º in his account of Virginia written about 1627. He says he drew his information from Pierce, Willoughby, Claiborne and others who had been here, and from his own father who had lived here 12. years. It does not appear whether the fact is stated on their own view or on information from the Indians. Probably the latter. The progress of the new population would soon drive off the larger animals, and the largest first. In the present interior of our continent there is surely space and range enough for elephants and lions, if in that climate they could subsist; and for mammoths and megalonyxes who may subsist there.34 Our entire ignorance of the immense country to the West and North West, and of it’s contents, does not authorize us to say what it does not contain. Moreover it is a fact well known, and always susceptible of verification, that on a rock on the bank of the Kanhawa near it’s confluence with the Ohio, there are carvings of many animals of that country, and among these one which has always been considered as a perfect figure of a lion. And these are so rudely done as to leave no room to suspect a foreign hand.35 This could not have been the smaller and36 mane-less lion of Mexico and Peru, known also in Africa both in antient and modern times, tho’ denied by M. de Buffon:º because, like the greater African lion, he is a tropical animal. And his want of a mane would not satisfy the figure. This figure then37 must have been taken from some other prototype, and that prototype must have resembled the lion sufficiently to satisfy the figure,38 and was probably the Animal the description of which by the Indians made Hawkins Harriot and others conclude there were lions here. May we not presume that prototype to have been the Great claw?39 Many traditions are in possession of our upper inhabitants, which themselves have heretofore considered as fables; but which have regained credit since the discovery of these bones. There has always been a story current that the first company of adventurers who went to seek an establishment in the county of Greenbriar the night of their arrival were alarmed at their camp by the terrible roarings of some animal unknown to them, that he went round and round their camp, that at times they40 saw his eyes like two balls of fire, that their horses were so agonised with fear that they couched down on the earth, and their dogs crept in among them, not daring to bark. Their fires it was thought protected them, and the next morning they abandoned the country. This was little more than 30. years ago.41—In the year 1765. George Wilson and John Davis having gone to hunt on Cheat river, a branch of the Monongehela, heard one night at a distance from their camp a tremendous roaring which became louder and louder as it approached, till they thought it resembled thunder and even made the earth tremble under them. The animal prowled round their camp a considerable time, during which their dogs tho on all other occasions fierce42 crept to their feet, could not be excited from their camp nor even encouraged to bark. About daylight they heard the same sound repeated from the knob of a mountain about a mile off and within a minute it was answered by a similar voice from a neighboring knob. Colo. John Stuart had this account from Wilson in the year 1769. who was afterwards Lieutt. Colo. of a Pensva. regiment in the revolution war, and some years after from Davies who is now living in Kentuckey. These circumstances multiply the points of resemblance between this Animal and the lion. º M. de la Harpe of the French academy in his abridgment of the General history of voiages speaking of the Moors, says ‘it is remarkeable that when during their huntings they meet with lions, their horses, tho’ famous for swiftness, are seized with such terror that they become motionless, and their dogs, equally frightened creep to the feet of their master or of his horse.’ Mr. Sparrman in his Voyage to the cape of good hope chap. 11. says ‘we could plainly discover by our animals when the lions, whether they roared or not, were observing us at a small distance. For in that case the hounds did not venture to bark, but crept quite close to the Hottentots; and our oxen and horses sighed deeply, frequently hanging back, and pulling slowly with all their might at the strong straps with which they were tied to the waggon. They also laid themselves down on the ground and stood up alternately, as if they did not know what to do with themselves, and even as if they were in the agonies of death.’ He adds that ‘when the lion roars, he puts his mouth to the ground, so that the sound is equally diffused to every quarter.’ M. de Buffon [XVIII. 31.] describes the roaring of the lion as, by it’s echos resembling thunder: and Sparrman c. 12. mentions that the eyes of the lion can be seen a considerable distance in the dark and that the Hottentots watch for his eyes for their government. The phosphoric appearance of the eye in the dark seems common to all animals of the Cat kind.43 The terror excited by these animals is not confined to brutes alone. A person of the name of Draper had gone in the year 1770. to hunt on the Kanhawa. He had turned his horse loose with a bell on, and had not yet got out of hearing when his attention was recalled by the rapid ringing of the bell. Suspecting that Indians might be attempting to take off his horse he immediately returned to him, but before he arrived he was half eaten up. His dog scenting the trace of a wild beast, he followed him on it,44 and soon came in sight of an animal of such enormous size, that tho one of our most daring hunters, and best marksmen he withdrew instantly and as silently as possible, checking and bringing off his dog.45 He could recollect no more of the animal than his terrific bulk and that his general outlines were those of the Cat kind. He was familiar with our animal miscalled the panther, with our wolves and wild beasts generally46 and would not have mistaken nor47 shrunk from them.

In fine, the bones exist; therefore the animal has48 existed. The movements of nature are in a never-ending circle. The animal species which has once been put into a train of motion, is still probably moving in that train. And if he be49 still in being, there is no reason to disbelieve50 the relations of honest men, applicable to him and to him alone. It would indeed be but conformable to the ordinary economy of nature to conjecture that she had opposed sufficient barriers to the too great multiplication of so powerful a destroyer. If lions and tygers multiplied as rabbets do,51 all other animal nature would have been long ago destroyed, and themselves would have ultimately extinguished after eating out their pasture. It is probable then that the Great claw has at all times been the rarest of animals. Hence so little is known and so little remains of him. His existence however being at length discovered, enquiry will be excited, and further information of him will probably be obtained.52

The cosmogony of M. de Buffon supposes that the earth and all the other planets, primary and secondary, have been masses of melted matter struck off from the sun, by the incidence of a comet on it: that these have been cooling by degrees, first at the poles, and afterwards more and more towards their Equators; consequently that on our earth there has been a time when the temperature of the poles suited the constitution of the Elephant, the Rhinoceros and Hippopotamos: and in proportion as the remoter zones became successively too cold, these animals have retired more and more towards the Equatorial regions till now that they are reduced to the torrid zone as the ultimate stage of their existence. º To support this theory he assumes the tusks of the Mammoth to have been those of an elephant, some of his teeth to have belonged to the hippopotamos, and his largest grinders to an animal much greater than either, and to have been deposited on the Missouri, the Ohio, the Holston when those latitudes were not yet too cold for the constitutions of these animals. He would of course then claim for the lion, now also reduced to the torrid zone and it’s vicinities, the bones lately discovered; and consider them as an additional proof of his system;53 and that there has been a time when our latitudes suited the lion as well as the other animals of that temperament. This is not the place to54 [observe that we have all seen the teeth55 of the Mammoth as well those ascribed to the Hippopotamos as those left to himself fixed in the same jaw and now in possession of Dr. Wistar one of the worthy Vicepresidents of our society56 in the city of Philadelphia, nor to] examine all the other weak points of this system, in which indeed almost all are weak and untenable. But let us for a moment grant this with his former postulata, and ask how they will consist with another theory of his ‘qu’il y a dans la combinaison des elemens et des autres causes physiques, quelque chose de contraire a l’aggrandissement de la nature vivante dans ce nouveau monde; qu’il y a des obstacles au developpement et peut-etre a la formation des grands germes.’ XVIII. 145. He says that the Mammoth was an elephant, º yet two or three57 times as large as the elephants of Asia and Africa. That some of his teeth were those of a Hippopotamus, yet of a hippopotamus four58 times as large as those of Africa [1. Epoq. 246. 2. Epoq. 232.] That the mammoth himself, for he still considers him as a distinct animal, ‘was of a size superior to that of the largest elephants,—that he was the primary and greatest of all terrestrial animals’ 2. Ep. 234. 235. We suppose him to claim the Megalonyx for a lion, yet certainly59 a lion of more than 3 times the volume of the African.60 I delivered to M. de Buffon the skeleton of our palmated elk called Orignal or61 Moose 7. feet high over the shoulders.62 He is often considerably higher. º I cannot find that the European elk is more than two thirds of that height consequently not one third of the bulk of the American. He acknoleges º the palmated deer (daim) of America to be larger and stronger than that of the old world. He considers the round horned deer º of these states and of Louisiana as the Roe and admits they are of three times his size. Are we then from all this to draw a conclusion the reverse of that of Monsr. de Buffon, that Nature,64 has formed the larger animals of America, like it’s lakes, it’s rivers and mountains on a greater and prouder scale than in the other hemisphere? Not at all. We are to conclude that she has formed some things large, and some things small on both sides of the earth for reasons which she has not enabled us to penetrate: and65 that we ought not to shut our eyes upon one half of her facts and build systems on the other half.66

To return to our67 Great claw, I deposit his bones with the Philosophical society as well in evidence of their existence68 and of their dimensions as for their safe keeping and I shall think it [my]69 duty to do the same by such others as I may be fortunate enough to obtain the recovery of hereafter.70

P.S.71 After the preceding communication was ready to be delivered in to the society, in a *periodical publication from London I met with an account and drawing of the skeleton of an animal dug up near the river la Plata in Paraguay and now mounted in the cabinet of Natural history at Madrid.72 The figure is not so done as to be relied on, and the account is only an abstract from that of Cuvier and Roumé. This skeleton is also of the clawed kind, and73 having only 4 teeth on each side above and below, all grinders,74 is classed in this account in the family of unguiculated quadrupeds destitute of cutting teeth75 and recieves the new denomination of Megatherium. Having nothing of our animal but the leg and foot bones, we have few points for a comparison between them. They resemble in their stature, that being 12 f.—9 I. long, and 6 f.—4 1/2 I. high, and ours by computation 5 f.—1.75 I. high: in the colossal thickness of the thigh and leg bones also. They resemble too in having claws, but those of the figure appear very small and the verbal description does not satisfy us whether the claw-bone or only it’s horny cover be large. They agree too in the circumstance of the two bones of the forearm being distinct and moveable on each other; which however is [believed]76 to be so common77 as to form no mark of distinction. They differ in the following circumstances if our relations are to be trusted. The Megatherium is not of the cat form, as are the Lion, tyger and panther, but is said to have striking relations in all parts of it’s body with78 the Sloth (Bradypus) tatoo (Dasypus) pangolin (Manis) and the anteaters (Myrmecophaga and Orycteropus.)79 According to analogy then it probably was not carnivorous, had not the phosphoric eye, nor leonine roar. But to solve satisfactorily80 the question of identity the discovery of fore teeth, or of a jaw bone shewing it had or had not such teeth, must be waited for and hoped with patience. It may be better in the mean time to keep up even81 the difference of name.

Dft (DLC: TJ Papers, 233: 41752–7); undated, but assigned from APS description begins American Philosophical Society description ends , Transactions, iv [1799], 258–9, which gives dates of 10 Feb. 1797 to the memoir and 10 Mch. 1797 to the postscript; consisting of a report written entirely in TJ’s hand on both sides of five unnumbered sheets, possibly copied in whole or part from an earlier missing draft, and a postscript on a sixth sheet; heavily emended, the most significant changes being recorded in notes below; with one query written in margin (see note 54 below); brackets in original except where noted; TJ’s block printing shown as small capitals; one passage and the location of one unkeyed insertion have been supplied from APS description begins American Philosophical Society description ends , Transactions (see notes 29 and 75 below); endorsed by TJ: “Megalonyx.” Although no fair copy in TJ’s hand has been found, variations between the Dft and the version printed by the American Philosophical Society suggest that one existed. Printed as “No. XXX. A Memoir on the Discovery of certain Bones of a Quadruped of the clawed Kind in the Western Parts of Virginia. By Thomas Jefferson, Esq.,” in APS description begins American Philosophical Society description ends , Transactions, iv [1799], 246–60; contains datelines and signature lacking in Dft (see notes 70–1 below); with variations of capitalization, punctuation, abbreviations, paragraphing, and spelling not recorded; significant variations in wording are recorded in notes below; TJ’s citations appear in printed version as footnotes keyed to text; at head of text: “Read March 10, 1797.” See Sowerby, description begins E. Millicent Sowerby, comp., Catalogue of the Library of Thomas Jefferson, Washington, D.C., 1952–59, 5 vols. description ends No. 3753.

With this paper TJ formally announced to the scientific world the discovery of fossilized skeletal remains of the mammal he called the megalonyx, now known to have been a form of extinct ground sloth of the Pleistocene epoch. The sequence of his work on the Dft is significant, given his late discovery of information he acknowledged in the postscript. Unfortunately, however, it is impossible to construct an exact chronology of his alterations to the manuscript. Presumably TJ himself, on a fair copy since lost, furnished the 10 Feb. 1797 dateline that appears in APS description begins American Philosophical Society description ends , Transactions. It is unlikely that he began composition of this “memoire” before 6 Feb. 1797, for on that day he received John Stuart’s letter of 16 Jan. announcing Stuart’s failure to locate the substantially intact femur from which TJ had hoped to calculate the creature’s size. In composing the memoir, TJ also drew on Stuart’s letter for dimensions of that missing thigh bone—one foot long, four and a quarter inches in diameter—rather than using conflicting information from Archibald Stuart, which TJ relied on as late as 22 Jan. 1797 (see Archibald Stuart to TJ, 19 Aug. 1796; TJ to Benjamin Smith Barton, 10 Oct. 1796; John Stuart to TJ, 16 Jan. 1797; and TJ to Benjamin Rush, 22 Jan. 1797).

That nearly complete thigh bone, reported to TJ but never seen by him, was distinct from the small fragment of the femur he listed first among the megalonyx specimens described in the above memoir. The fragment proved elusive in its own way. As important as the femur was to TJ’s deductions of the size of the megalonyx, his scientific contemporaries were unable to utilize even a piece of that bone in drawing conclusions about the animal. Perhaps due to uncertainty over its identification, Caspar Wistar did not discuss the fragment mentioned in the memoir in a descriptive report he prepared on the megalonyx specimens (published, with illustrations from drawings by Titian Peale and Dr. W. S. Jacobs, as “No. LXXVI. A Description of the Bones deposited, by the President, in the Museum of the Society, and represented in the annexed plates,” APS description begins American Philosophical Society description ends , Transactions, iv [1799], 526–31). After studying casts of the bones sent to Paris in 1802 by Charles Willson Peale, the French natural scientist Georges Cuvier—who in 1796, on the basis of information obtained in Spain by Philippe Rose Roume (roumé), had described the South American Megatherium—was unsure whether the piece had come from a femur or a humerus, and concentrated his analysis on other features (Cuvier, “Mégalonix,” description begins Georges Cuvier, “Sur le Mégalonix, Animal de la famille des Paresseux …,” Annales du muséum National d’Histoire Naturelle, V, 1804, 358–75 description ends 359; Peale to Cuvier, 16 July 1802, in PPAmP: Peale—Sellers Papers; Boyd, “Megalonyx,” description begins Julian P. Boyd, “The Megalonyx, the Megatherium, and Thomas Jefferson’s Lapse of Memory,” Proceedings of the American Philosophical Society, CII, no. 5, 1958, 420–35 description ends 429).

TJ’s initial misidentification of another bone, the radius, is reflected in his deletion from the Dft of references to the tibia (see notes 9 and 26–7 below). In his early analysis of the megalonyx remains he concluded that one bone was a tibia, a bone of the hind leg, for he would not otherwise have stated that the recovery of a complete thigh bone would mean that “we should possess a whole limb from the haunch bone to the claw inclusive” (TJ to John Stuart, 10 Nov. 1796). He maintained the notion that one of the fossils was a tibia as he penned the Dft, which originally made no mention of a radius. He subsequently revised his identification of the bone, and, in addition to substituting “radius” for “tibia” throughout, altered the sequence of entries in the table of measurements. Originally in the table he had placed entries for the “tibia” below those for the femur, thus grouping together what he thought were measurements of two long bones of the hind limb. After realizing that the supposed “tibia” was actually a radius, a bone of the forelimb, he revised the table to put those entries closer to the measurements of the bone’s proper anatomical neighbor, the ulna (see notes 12–19 below).

According to his Memorandum Books, TJ left Monticello for Philadelphia on 20 Feb. and arrived in the capital late on 2 Mch. 1797. Although he possibly discovered the “tibia” error on his own and made those alterations to the Dft before his departure from Monticello, it seems likely that he only learned of his mistake when the fossils were seen in Philadelphia by a more expert anatomist such as Wistar. If so, TJ made the changes substituting the radius for the tibia in the period between his arrival in Philadelphia and the reading of the memoir to the Philosophical Society on 10 Mch. 1797. The society actually met on the evening of 3 Mch. with TJ, its newly elected president, in attendance, but after dealing with some other business adjourned for a week “on the account of a Communication to be made, before Mr. Jefferson leaves the City” (PPAmP: Ms. Minutes, 3 Mch. 1797). The minutes do not indicate whether the group originally expected to receive TJ’s memoir on the 3d or, if so, whether the postponement was due to any need for him to revise the paper.

If he made a fair copy of the manuscript it stands to reason, but is not certain, that he did so before submitting the memoir to the society on the evening of 10 Mch., and that he did not alter the Dft after making the fair copy. Evidently sometime between his arrival on the 2d and the society’s meeting on the 10th he saw in the September 1796 issue of the monthly magazine the notice of Cuvier’s description of the megatherium that impelled him to write the postscript (see Sowerby, description begins E. Millicent Sowerby, comp., Catalogue of the Library of Thomas Jefferson, Washington, D.C., 1952–59, 5 vols. description ends No. 682). It has been suggested that he wrote the postscript not long before the society’s 10 Mch. meeting and also made hurried changes to the Dft in light of the megatherium discovery, assigning the megalonyx to a general category of clawed animals rather than the family of large feline predators (Boyd, “Megalonyx,” description begins Julian P. Boyd, “The Megalonyx, the Megatherium, and Thomas Jefferson’s Lapse of Memory,” Proceedings of the American Philosophical Society, CII, no. 5, 1958, 420–35 description ends 425–6). Two months later, however, he continued to identify the creature as “a carnivorous animal” (TJ to Louis of Parma, 23 May 1797). The title of TJ’s “memoire” is recorded in the society’s minutes as “On the Discovery of certain Bones of a Quadruped of the  ”—the blank suggesting that the issue of the beast’s classification was not fully resolved at the time of the meeting. We may never know what taxonomic language appeared in the paper as Jonathan Williams, in his capacity as one of the society’s secretaries, read it aloud to the group with TJ in the presiding chair (PPAmP: Ms. Minutes, 10 Mch. 1797).

Not all alterations to the Dft were necessarily late changes. For example, one set of emendations involved the removal of John Smith’s observations from the anecdotal evidence TJ related in support of his contention that a gigantic predatory mammal still roamed North America (see notes 32 and 38 below). TJ was a close student of early Virginia history and, according to Sowerby, description begins E. Millicent Sowerby, comp., Catalogue of the Library of Thomas Jefferson, Washington, D.C., 1952–59, 5 vols. description ends owned the books he cited on the subject. In this case, although he might have altered the passage relating to Smith after discussing his findings with others in Philadelphia, he could well have made those emendations as he prepared the Dft at Monticello in February. Barring discovery of new information, the various stages of the document’s composition and revision remain enigmatic.

Although unmindful of the fact when he saw published accounts of the specimen in 1797, TJ had some years earlier been sent a description and sketch of the South American megatherium skeleton preserved in Spain (see William Carmichael to TJ, 26 Jan. 1789, and enclosure; and above in this series, Vol. 14: xxv–xxxiv).

In 1804 Cuvier, rejecting any association of the megalonyx with catlike meat eaters, demonstrated that both it and the megatherium were herbivores related to modern sloths. He also considered the two animals, because of a substantial difference in size, to be different species within the same genus, thus explicitly contradicting French geologist Barthélemy Faujas de Saint-Fond, who called both animals “mégalonix” and refused to classify them with the sloths. Cuvier’s analysis therefore reinforced TJ’s call for preserving the difference of name pending further study. Wistar, too, in his report on the megalonyx bones, had noted apparent anatomical differences between the animals. However, by 1803 TJ himself believed that the megalonyx and the megatherium were probably the same, and when he became aware that Cuvier and Faujas were “rather at war” over classification of the beasts, he did not consider the arguments of the former to be conclusive. He applied Faujas’s term “artificial” to Cuvier’s taxonomy (Cuvier, “Mégalonix,” description begins Georges Cuvier, “Sur le Mégalonix, Animal de la famille des Paresseux …,” Annales du muséum National d’Histoire Naturelle, V, 1804, 358–75 description ends 358–75; Cuvier, “Sur le Megatherium, Autre animal de la famille des Paresseux …,” Annales du Muséum National d’Histoire Naturelle, 5 [1804], 376–87; TJ to Lacépède, 24 Feb. 1803; TJ to John Vaughan, 15 Aug. 1805). Nevertheless, modern paleontology, like Cuvier’s work, makes a clear distinction between the animals, classifying the megalonyx and the megatherium in separate families of prehistoric ground sloths. To recognize TJ’s role in publicizing the discovery, in 1822 another French scientist, Anselme Desmarest, labeled the Virginia specimen Megalonyx jeffersonii, the name by which the species is still known (Björn Kurtén and Elaine Anderson, Pleistocene Mammals of North America [New York, 1980], 135–8; Greene, American Science description begins John C. Greene, American Science in the Age of Jefferson, Ames, Iowa, 1984 description ends , 284).

1Line lacking in APS description begins American Philosophical Society description ends , Transactions.

2Preceding two words interlined in place of “family of the lion, tyger, panther &c.”

3APS description begins American Philosophical Society description ends , Transactions: “a Quadruped.”

4Word interlined in place of “Unguiculated.”

5APS description begins American Philosophical Society description ends , Transactions: “Cromer.”

6APS description begins American Philosophical Society description ends , Transactions: “The nitrous impregnation of the earth together with a small degree of petrification had probably been the means of their preservation.”

7Word interlined in place of “children and others.”

8Word interlined in place of “symphysis.”

9Preceding two words written over erased “[Tibia] […], perfect,” with an estimated three illegible words in the middle of the erasure. In the next line, “an Ulna” is written over an illegible erasure.

10Sentence to this point interlined in place of “These bones, and particularly the claws, sufficiently characterize the animal to a species […] of the same species with the lion, tyger, panther, etc.”

11Here and at two other occurrences of the word in this table, TJ interlined “Ulna” in place of “Cubit.”

12Line inserted in place of “diameter of the middle of the femur 4.25 1.15.”

13Line inserted in place of “hollow of the femur at the same place [1.25].”

14Line inserted in place of “thickness of the bone surrounding the hollow [1.5].”

15Line inserted.

16Below this line TJ originally wrote an entry that read “length of the tibia or shank bone 17.75 12.37.” He subsequently interlined “Radius” in place of “tibia” and canceled the entire line.

17TJ originally wrote “diameter of Radius.” He wrote this entire line in place of “breadth of the tibia at it’s head,” followed by illegibly canceled measurements. He also illegibly canceled another pair of measurements below that line.

18Line inserted in place of “circumference at it’s middle 7.4 3.62.”

19Line inserted in place of “breadth at it’s lower extremity,” followed by illegibly canceled measurements that TJ evidently replaced with “4.05 1.18,” which he also subsequently canceled. He also drew a bracket enclosing the canceled entries recorded in this and preceding three notes.

20Word interlined in place of “carpus or tarsus.”

21APS description begins American Philosophical Society description ends , Transactions: “It is actually 6 3/4 inches long, but about 3/4 inch appear to have been broken off.”

22APS description begins American Philosophical Society description ends , Transactions: “Actually 5.65 but about 1/4 inch is broken off.”

23Word interlined. At the beginning of this sentence TJ canceled “from the general conformity of his bones with those of the lion.”

24Both occurrences of “an Ulna” in this sentence are interlined in place of “a cubit.”

25Preceding three words interlined in place of “was.”

26Sentence interlined in place of canceled “M. Daubenton not having given us the diameter of the <Cubit> ulna of his lion, we can only compare the hinder limb.” TJ also interlined and canceled “the tibia of the lion was 3.62 Inches in circumference at the middle. That of the Megalonyx [7.4] I. which is more than the double.”

27Preceding two words interlined in place of “times as great.” TJ interlined the next two sentences and the beginning of the succeeding sentence through “that he was” in place of canceled “as the tibia of the lion was 3.62 I. in circumference at the middle: that of the Megalonyx 7.4 I. which is more than the double. And as bones of the same length have their bulks proportioned to the squares of their diameters, this would lead to much stronger conclusions. It is possible however that the flesh of this animal might not exceed that of the lion in the same degree with his bones so that it is safest to conclude only in the general that he was considerably.”

28Preceding two words interlined in place of “the lion, tyger and panther.”

29Passage ends here at foot of a page; remainder of sentence supplied from APS description begins American Philosophical Society description ends , Transactions.

30TJ here canceled “I rather believe they do not.”

31Word interlined. TJ originally wrote “actual research and enquiry into the subject.”

32TJ interlined the next twelve sentences in place of the following passage, with his brackets enclosing the citation to John Smith’s History: “in the interior country of our continent there is surely space and range enough for elephants and lions, if that climate suited them and for mammoths and megalonixes whom it does suit. Our entire ignorance of the immense <space> country to the West and N. West and of it’s contents, does not authorize us to say what it does not contain. When capt. Smith who first effected the permanent settlement of our colony landed here in 1607 the Indian population below the falls of the rivers was about the twentieth part of what it now is: and the Indians having no flocks of domestic quadrupeds or fowls and little culture there was nothing to tempt the greater animals to remain among them or near them, while their perpetual hunting would be a cause for their retiring to a distance. Yet Capt. Smith [Hist. Virga. pa. 10.] mentions the lion among the game sometimes brought in and eaten by the Indians and speaks of a lion skin used as a mattres. Now certainly the animal we miscall a panther, or any other animal of our woods could not have been mistaken by capt. Smith for a lion. He had served many years in the […] of the Turks in Europe and Asia, had been a very general traveller, and could not have been altogether unacquainted with the lion.”

33TJ here canceled “(doubtless the Great claw).”

34TJ first wrote “to whom it is adapted,” then altered the clause to read as above.

35TJ wrote the next two sentences as an insertion beginning on the line and continuing in the margin, probably adding the second sentence sometime after writing the first. He placed the citations at the edge of the margin alongside the insertion.

36TJ here canceled “injubate.”

37TJ first began the sentence “But as there was no lion here, that” before altering it to read as above.

38Remainder of sentence interlined in place of “and sufficiently to impose on Capt. Smith.”

39Preceding two words interlined in place of “Megalonyx.”

40TJ first wrote “that they often,” then altered the phrase to read as above.

41TJ first wrote “probably about between 30. and 40. years ago” before altering the passage to read as above.

42Preceding six words interlined.

43Sentence interlined.

44TJ first wrote “he perceiving the tract of a wild beast and following on it,” then altered the passage to read as above.

45For the portion of the sentence following “marksmen,” TJ first wrote and canceled “he lost the powers of his mind, and fled from irresistable instinct,” then by successive changes altered the passage to read as above.

46Preceding eleven words interlined in place of “panthers, wolves and such animals.”

47Preceding two words inserted in margin.

48TJ first wrote “must have,” then altered the words to read as above.

49Preceding two words interlined in Dft in place of “it is.”

50In place of sentence to this point, APS description begins American Philosophical Society description ends , Transactions reads: “For if one link in nature’s chain might be lost, another and another might be lost, till this whole system of things should evanish by piece-meal; a conclusion not warranted by the local disappearance of one or two species of animals, and opposed by the thousands and thousands of instances of the renovating power constantly exercised by nature for the reproduction of all her subjects, animal, vegetable, and mineral. If this animal then has once existed, it is probable on this general view of the movements of nature that he still exists, and rendered still more probable by.”

51APS description begins American Philosophical Society description ends , Transactions here adds “or eagles as pigeons.”

52TJ evidently inserted this paragraph in space he left on the page during his initial drafting.

53In APS description begins American Philosophical Society description ends , Transactions sentence to this point reads: “Should the bones of our animal, which may hereafter be found, differ only in size from those of the lion, they may on this hypothesis be claimed for the lion, now also reduced to the torrid zone, and its vicinities, and may be considered as an additional proof of this system.”

54Here in margin TJ wrote “qu. the fact?” In APS description begins American Philosophical Society description ends , Transactions remainder of sentence reads “discuss theories of the earth, nor to question the gratuitous allotment to different animals of teeth not differing in any circumstance.”

55Word interlined in place of “grinders,” which TJ had previously interlined in place of “teeth.”

56TJ first wrote “one of our worthy members.”

57Preceding three words interlined in place of a canceled word, possibly “six.”

58Word interlined in place of a canceled word, possibly “nine.”

59In APS description begins American Philosophical Society description ends , Transactions sentence to this point reads “If the bones of the megalonyx be ascribed to the lion, they must certainly have been of.”

60TJ here wrote and canceled “He says that our Moose is a Renne.”

61Preceding five words written in margin.

62TJ interlined the next four sentences in place of the following canceled passage: “The [Renne] is but of   feet. The American then is of   times the volume of the European. The animal which we miscall a panther, he calls a Cougar. I delivered to him the stuffed skin of one 2. or 3. times greater than the Cougar of  . He says that our deer is the Roe. Yet all who have seen <the> our deer <of America> and the Roe of Europe, and thousands have seen both, know that the former is of 3. or 4. times the bulk of the latter.”

63APS description begins American Philosophical Society description ends , Transactions lacks citation to works by Catesby and Kalm.

64TJ here canceled “whatever she may have done as to smaller animals and objects.”

65Preceding two words interlined in place of an illegible word and “discover.”

66TJ originally continued this sentence with a semicolon and the following passage, which he subsequently canceled: “and that it is better to confess ignorance in things not made than to propagate error <in things> on subjects not made for our comprehension.”

67TJ here canceled “Megalonyx.”

68Having filled the sheet, TJ wrote the remainder of this sentence in the margin.

69Word torn, supplied from APS description begins American Philosophical Society description ends , Transactions.

70Here APS description begins American Philosophical Society description ends , Transactions adds a signature, “TH: JEFFERSON,” and “Monticello, Feb. 10th, 1797.”

71Here APS description begins American Philosophical Society description ends , Transactions adds: “March 10th, 1797.”

72TJ here canceled “this […] skeleton is also.”

73TJ here canceled “wanting front.”

74Remainder of sentence interlined in place of “falls into the linnaean class of  .”

75TJ wrote the preceding four words in the margin without keying their intended location. Placement of the phrase here follows APS description begins American Philosophical Society description ends , Transactions.

76Word supplied from APS description begins American Philosophical Society description ends , Transactions. Dft: “beloved.”

77APS description begins American Philosophical Society description ends , Transactions: “usual.”

78In APS description begins American Philosophical Society description ends , Transactions remainder of sentence reads “the bradypus, dasypus, pangolin, &c.”

79TJ here canceled “it has not then probably the phosphoric eye. Probably also it is not carnivorous. The Leonine roar,” then interlined and canceled “according to analogy then with this family it probably is not carniv.”

80Word interlined.

81Word lacking in APS description begins American Philosophical Society description ends , Transactions.

Authorial notes

[The following note(s) appeared in the margins or otherwise outside the text flow in the original source, and have been moved here for purposes of the digital edition.]

º A Memoire On the Discovery of certain bones of an Animal3 of the clawed4 kind in the Western parts of Virginia.

* Buffon XVIII. 38. of the Paris edition in 31. v. 12mo

 2. De Manet. 117.

* supposing 3/4 I. of the point broken off.21

 supposing 1/4 I. of the point broken off.22

* Buff. XXII. 121.

 Buff. XVIII. 15.

º Hakluyt 541. edition of 1589. id. 757. Smith’s Hist. Virga. 10.

º Bullock pa. 5.

º Arist. Anim. 9.4. Plin. VIII. 16 Kolbe Buff. XVIII. 18

º G’ent. & Lond. magazine for 1783.

º 2. Epoq. 233. 234.

º 2.Ep.223.

º 1. Catesby. Kalm I. 232. II.340.63

º XXIX. 245

º XII. 91.92. XXIX. 245. V. Supplem. 201.

* Monthly Mag. Sep. 1796.

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