204 
EDENTATES. 
laying Mammals. It is further noteworthy that while among the ant-eating 
Edentates the true ant-eaters and the pangolins have entirely lost their teeth, those 
organs are retained in a comparatively high state of development among the aard- 
varks. At the present day the Edentates are evidently a waning group, the whole 
of the larger members of the order having died out; while those which remain 
have sought protection by the acquisition of either arboreal or burrowing habits, 
or by the development of a protective coat of mail to their bodies. 
The Sloths. 
Family Brad YPODID^E. 
Although by the older zoologists the sloths were regarded as ill-formed 
creatures destined to lead a miserable life on account of their misshapen limbs, 
no animals are in reality better adapted to their peculiar mode of existence. We 
see this not only in their elongated limbs, which have been modified into hook-like 
organs of suspension, with the removal of all superfluous digits and the great 
development of the claws of those which remain; but likewise in the extraordinary 
resemblance of their coarse coat of hair to the shaggy lichens clothing the gnarled 
and knotted boughs of their native forests. It is noteworthy that while the monkeys 
of the same regions have mostly acquired a fifth limb by the development of the 
prehensile power in their tails, the sloths have almost dispensed with tails 
altogether. 
The sloths are characterised externally by their short and 
Characteristics. j j 
rounded heads, m which the ears are very small and buried among 
the fur, their rudimentary tails, and the excessive elongation of their fore-limbs, of 
