664 Marvels of the Universe 
putting these facts together, it has been supposed 
—and there seems nothing extravagant in the 
supposition—that the Indians who made the tools 
of bone and chopped the hay, kept and fed these 
Ground Sloths to slaughter them, as required, for 
their own food! 
Another interesting peculiarity about the pieces 
of skin above referred to is that they were 
thickened and strengthened by a quantity of 
close-set bones resembling small pebbles, show- 
ing that this Mylodon-like Ground Sloth was 
invested in a tough, bony coat almost as resisting 
and flexible as chain-armour. The zoological in- 
terest of this fact les in the kinship it suggests 
between these creatures and the South American 
armadillos, which likewise have bony plates in the 
skin, and are known to be related to the Sloths 
and Ant-eaters. 
Thus the study of this group of animals, known 
to zoologists as the Edentata, shows how the 
small and insignificant species, which lurk in the 
THE SHELL OF A TORTOISE. 
The Tortoise can shut himself up in his fortress 
tree-tops or skulk on the ground, have outlived 
the huge and unwieldy forms in the contest for 
against all enemies. In this case the lower part of his 
shell is hinged so that he can draw it up and shut existence. 
himself entirely in. 
ONY Wale TORTOISE, GOW IelS Slave vie 
BY W. P. PYCRAFT, F.Z.S. 
“ FAMILIARITY,” it has been well said, ‘‘ breeds contempt,” and this was certainly never more 
true than of the Tortoise. If this were as rare an animal, say, as an Okapi, we should all of 
us, long ago, have discovered that it was one of the most remarkable of living animals. As 
it is, some may wonder why it is accorded a place among the “ Marvels of the Universe.” 
Yet, of living creatures, 
none more thoroughly de- 
SAEs me, lin Was iavesit 
place, it stands alone 
among the vertebrates— 
or backboned animals— 
in having its skeleton out- 
side its body, just like 
““a mere Beetle.’ How 
has this come about 2 In 
all other vertebrates, as in 
man himself, for instance, 
the backbone is embedded 
in a mass of muscle— 
which we in common 
speech call “ flesh” ; and 
the back is lithe, it himself secure. 
THE SHELL OF A TORTOISE. 
In this species it is the upper part, so that he can draw it down and make 
