22 EIGHTEENTH ANNUAL REPORT ON THE STATE CABINET. 



dom. To the tongue of a Giraffe and the proboscis of a Tapir, there wag 

 added the power of rotating the I ones of the forearm. These prehensile 

 organs were suited to a leaf-feeder. That the animal was not carnivorous, is 

 settled by the structure of its molar teeth : it lacks incisors ; therefore it 

 was not a Kuminant. But if the great animal fed on foliage, how did it ob- 

 tain it? The Elephant gathers its food with a long proboscis. The Giraffe, 

 standing on stilt-like forelegs, and reaching out its attenuated neck, plucks 

 the high branches with long flexible lips and muscular tongue. The Mega- 

 therium could imitate neither. Did it climb like the Sloth? Such was the 

 conjecture of the Danish Naturalist, Dr. Lund ; but the clumsy make and 

 the immense bulk and weight of the creature forbid it. The structure of the 

 forefeet, moreover, militates against the theory ; for the outer digit is hoof- 

 like, as if made for terrestrial progression. The hindlegs, too, are much 

 shorter than the forelegs ; and the tail is too short and thick for prehensile 

 purposes. 



The fossorial hypothesis, too, has no better foundation than the scansorial. 

 In burrowing animals, as the Mole, the pelvis is remarkably slender, and 

 the claws form a continuous plane with the palm of the foot ; while in the 

 Megatherium the pelvis is remarkably large, and not one of the claws can 

 be brought into a line with the metacarpus. The fore-arms were plainly 

 formed for grasping, not climbing nor dinging : they were instruments of 

 tremendous strength, evidence of which is furnished by the deep grooves and 

 sharp ridges on the radius and ulna, the starting points of stout tendons and 

 muscles. The moment we estimate this force, the colossal proportions of the 

 hind-extremities lose their anomaly and harmonize with the front. The ap- 

 plication of the fore-arms to the work of tearing down a tree would demand 

 a corresponding fulcrum, such as we find in the heavy pelvis, the ponderous 

 tail and the massive hindlegs. 



The Megatherium needed not agility for securing prey, for it was not 

 carnivorous ; nor for flight, for its size alone must have been a protection 

 against any living foe. Had we beheld it living on its native plains, its slow 

 movement would have excited our wonder as much as its bulk. It was 

 doubtless a solitary animal. The gathering together in herds was not required 

 for self-defence : indeed, the necessities of the creature to obtain an enor- 

 mous daily supply of food would not have allowed it, unless the vegetation 

 of that day were far more dense than is the modern vegetation of the same 

 region. When stripping the trees it had prostrated, its position was probably 

 a reclining one ; and Professor Agassiz has ventured the opinion that this 

 crouching attitude was constant to the animal, and that it crept along with 

 the full length of its fore-arm resting upon the ground. 



The Pampas, where the remains of the great fossil have been chiefly 

 found, are vast plains, stretching from the mountains of Brazil to Tierra 

 del Fuego. Palms grow at one end, while snow covers the other almost the 

 entire year. The soil is chiefly a dull-reddish slightly-indurated argillaceous 

 earth, with here and there calcareous concretions : underneath are beds of 

 stratified gravel and conglomerate. These deposits constitute the Pampean 

 formation, which varies in depth from twenty to one hundred feet. They 

 were slowly formed at a time when the Atlantic reached far westward to the 

 foot of the central mountain chain, down whose flanks the rivers brought the 

 detritus and spread it beneath the waters in level layers at some distance 

 from the shore. Carcases of animals floated down upon the same streams, 

 and, reaching the quiet waters, sank down in their muddy bed. The whole 

 area has since been elevated ; the estuary mud has been converted into wide 

 and level plains, and the shores and submarine banks of a former sea now 

 form low headlands along the present coast. It was in this recent formation 



