336 MAMMALS 



back out of the way, tlnis ex]:)osing the claws so necessary 

 for digging its 1)uito\vs. The sjiiiiy ant-eater is furnished 

 witli strong claws for tearing ojjen the ants' nests. In 

 ad(.lition, it has a long, sticky, extensile tongue with which 

 it can lick up the ants by the hundred and tlius obtain a 

 meal. 



The sloth passes its existence in trees. Yet how curiously 

 adapted to such a life it is. W'liat wonderful muscles it 

 niu.st have never to weary of hanging down, either in its 

 waking or .sleeping moments. Try the exix'riment of hold- 

 ing your own weight by suspending yourself from a bar, 

 by your ai'ins, for five minutes. It will give an idea of 

 what the sloth's mode of life means to its muscles. Note 

 that the claws are also modified for gras])ing the branches. 

 Many .-^loths ])o.ssess hair resemf)ling lea\-es in color, thus 

 affording them protection. I suspect tliey were di'iven to 

 such a mode of living partlj' for the sake of protection. The 

 armadillo, however, which belongs to the same order, in- 

 stead of (liiiil)ing trees took upon hiins(>lf a coat of armor, 

 so flexible that he can I'oll u]) inside of it for protection. 



Perhaps among mammals the most icmarkable molli- 

 fications and adaptations are found among the whales. 

 As a class, mammals are tei'reslital ; but here \\(' Hnd an 

 order whicli is wliolly water-li^■ing. The>' are so far modi- 

 fied as to have lost one jiair of legs, wholly unfitting them 

 for a terrestrial life; and the second pair is modified into 

 very efficient paddles. Again, the tail is ada]ited to swim- 

 ming, and the body is covei'ed with a very thick layer of fat 

 to ])rotect them from the intense cold met with in their 

 habitats. Idie bowhead whale has no teeth and a very 

 small thr(.)at, hence cannot li\'e on la,i-ge animals or on gross 

 vegetable bodies. It, however, has an enormously capa- 



