178 SKETCH OF THE HISTORY OF MAMMALIA. 



mylodon fed on leaves, like the sloths of the present 

 day. But, notwithstanding Dr. Lund's opinion, it was 

 certainl}^ not adapted for climbing trees ; besides, what 

 trees could bear its weight ? How then did it obtain 

 its food ? The whole of its osseous conformation suggests 

 the answer — it was formed to uprend the trees that bore 

 its sustenance. The enormous expanse of the pelvis, 

 the great bulk and strength of the hind-legs, the so- 

 lidity of the tail, to which its evidently vast muscles were 

 attached, enabling it with the hind-limbs to complete a 

 firm tripod of support, the proportions of the fore-limbs, 

 unequalled for massiveness by those of any existing or 

 extinct animal, the size and strength of its claws, — in 

 short the whole mechanism of the colossal frame be- 

 comes intelligible only on the ground of the herculean 

 labour to which the animal was appointed. Perhaps it 

 commenced the process of prostrating the chosen tree by 

 scratching away the soil from the roots, and then pro- 

 ceeded to grapple with it thus partially undermined, and 

 apply the surpassing strength of its limbs and body, the 

 muscles of the trunk and extremities being animated by 

 the influence of the unusually large spinal chord. 



It may here be stated that the skull of the specimen 

 described by Professor Owen had at some time or other 

 been fractured and had healed ; the animal living long 

 afterwards : and it will at once occur to the reader that 

 these animals must have been unusually liable, from their 

 habits, to blows from heavy falling bodies ; to meet 

 such accidents the skull was peculiarly constructed, its 

 outer and inner table being separated by extensive air- 

 cells, so that the fracture of the outer tai3le might occur 

 without injury to the brain. It was by virtue of this 

 structure that the subject of the Professor's memoir 

 appears to have been saved. 



SCELIDOTHERIUM. 



Our Figures represent — Fig. 110, the remains of the 

 skull ; Figs. Ill, 112, the dentition of an extinct animal, 

 to which Professor Owen has given the title of Scelido- 

 therium. Figs. 113, 114, show the depth of the im- 



