204 EVOLUTION IN THE PAST 



strength, or at any rate from size to size. This progress was 

 noticeable in the Pliocene, and, in the course of the Pleistocene, 

 the animals assumed in some cases colossal proportions. 

 Sloths raised upon their hind-legs were gathering foliage 

 twenty feet from the ground {Megatherium Americanum). 

 In order to take their meals in comfort, they doubtless 

 arranged the limbs and long bony tail in old Dinosaurian 

 style so as to constitute a sort of three-legged stool. Thus 

 seated they proceeded, we may suppose, to bend down the 

 tree-branches with their arms, and to tear off the foliage with 

 their long, curling tongues. Most of the time not spent in 

 eating was probably devoted to sleep. Some of them (Mylo- 

 don) possessed a certain amount of bony armour embedded 

 in the hide, and thus protected slept, no doubt, all the more 

 soundly. 



Some imposing representatives of armadiUo-life were 

 now on the scene in the form of gigantic glyptodonts. Daedi- 

 curus stands out as the most extraordinary of these. His 

 length from nose to tail-end was about twelve feet. The top 

 of his head was protected by a bony cap, and his body by a 

 rigid carapace. The tail, which contributed five feet to his 

 total length, was encased partly by rings of bone and partly 

 by a tube of like substance, enlarged and well-spiked at the 

 end. The tail, with its armour, must have been of immense 

 weight, and it is difficult to imagine that it ever left the 

 ground. Elaborate armature was, no doubt, a much-needed 

 protection to Dsedicurus, for he was poorly endowed with 

 brains, phlegmatic in temperament, and probably whoUy lack- 

 ing in courage. 



Other glyptodonts were abroad that equalled Daedicurus 

 in total length, but they were longer in the body, and 

 shorter in the tail (Glyptodon clavipes). Their tails, moreover, 

 tapered to a point. It is not likely that the appendage 

 responded to happy sensations of head or heart, but it was 

 certainly more manageable than the heavy, battle-axe tail of 

 Daedicurus. 



The peculiar South American hoofed animals had also 

 increased in stature. Toxodonts — in Miocene times looking as 

 though coneys had grown to the size of sheep — were now in 



