GIANT SLOTHS AND ARMADILLOS. 179 
Mr. Clift’s memoir above quoted. But even then the materials 
were not complete for a thorough knowledge of the bony frame- 
work of the Megatherium, and it was not till 1845, when more 
remains (discovered near Luxan, 1837) reached this country, that 
Professor Owen was able to clear up one or two doubtful details. 
These were purchased by the trustees of the British Museum, 
and casts of the bones were taken. Among the various writings 
by learned men on the subject, Professor Owen’s masterly 
description stands pre-eminent ; indeed, he was the only one to 
solve the riddle, to thoroughly explain the structure of this 
giant sloth, and to show how its food was obtained.’ Neither 
Cuvier, nor the German doctors, nor Mr. Clift had succeeded in 
so doing. , 
In the Natural History Museum (Stand O, Gallery No. 2 on 
plan) is a cast representing the animal nearly erect, and grasping 
a tree. This magnificent cast (see Plate XVII.) represents an 
animal eighteen feet in length, and its bones are more massive 
than those of the elephant. For instance, the thigh-bone is nearly 
thrice the thickness of the same bone in the largest of existing 
elephants, the circumference being equal to the entire length. 
To a comparative anatomist several striking indications of great 
strength present themselves ; thus, not only the very forms of the 
bones themselves mean strength, but their surfaces, ridges, and 
crests are everywhere made rough for the firm attachment of 
powerful muscles and tendons. In the fore part of the body the 
skeleton is comparatively slender, but the hind quarters show 
enormous strength and weight combined. The tail, also, is very 
powerful and massive. The fore limbs are long, and evidently 
constructed for the exertion of great force. How this force was 
applied we shall see presently. In both sets of limbs we notice 
1 His views are expounded in his Memoir on the Megatherium, or Giant 
Ground Sloth of America, 1861, which is beautifully illustrated. The Royal 
Society gave £100 (part of a Government grant of £1000) to enable Professor 
Owen to carry out this important work. 
