the Megatherium. 363 



one being provided with a proboscis, and the entire frame of 

 the lofty Giraffe adapting it to browse on branches above the 

 reach of its largest ruminant congeners. If the Megatherium 

 possessed, as Cuvier conjectured, a proboscis, it cannot, judg- 

 ing from the suborbital foramina, have exceeded in size that 

 of the Tapir, and could only have operated upon branches 

 brought near its mouth. Of the use of such a proboscis in 

 obtaining nutritious roots, on the prevalent hypothesis that 

 such formed the sustenance of the Megatherium, it is not 

 easy to speculate ; the hog's snout might be supposed to be 

 more serviceable in obtaining those parts of vegetables ; but 

 no trace of the prsenasal bone exists in the skull. A short 

 proboscis would be very useful in rending oflF the branches of 

 a tree prostrated and within reach of the low and broad- 

 bodied Megatherium, and it would be aided in this act by 

 the tongue, of which, both the hyoid skeleton, by its strength 

 and articulation, and the foramina for the muscular nerves 

 by their unusual area, attest the great size and power. 



As regards the limbs, the Megatherium differs from the 

 Giraffe and Elephant in the unguiculate character of certain 

 of its toes, in the power of rotating the bones of the fore- 

 arm, in the corresponding development of supinator and ento- 

 condyloid ridges in the humerus, and in the possession of 

 complete clavicles. These bones are requisite to give due 

 strength and stability to the shoulder-joint for varied actions 

 of the fore-arm, as in grasping, climbing, and burrowing ; 

 but they are not essential to scansorial or fossorial quadru- 

 peds ; the Bear and the Badger have not a trace of clavicles, 

 and the mere rudiments of these bones exist in the Rabbit 

 and the Fox. We must seek, therefore, in the other parts 

 of the organization of the Megatherium, for a clew to the 

 nature of the actions by which it obtained its food. In 

 habitual burrowers the claws can be extended in the same 

 plane as the palm, and they are broader than they are 

 deep. In the Megatherium the depth of the claw-phalanx 

 exceeds its breadth, especially in the large one of the middle 

 finger ; and they cannot be extended into a line with the 

 metacarpus, but are more or less bent. Thus, although they 

 might be used for occasional acts of scratching up the soil, 



