150 NEIGHBORS WITH CLAWS AND HOOFS. 



he would always be either shivering or else unbearably 

 hot. Nature, therefore, has given him a thick layer of fat 

 between the skin and the muscles. 



13. In the water the hippopotamus, though a gigantic 

 beast, shows very little of his carcass. On referring to the 

 engraving, it will be observed that the nostrils, eyes, and 

 ears are on the same level. The nostrils are each provided 

 with a wonderful valve, by means of which he can open 

 his nostrils to breathe, or shut them up to exclude the 

 water. This beautiful mechanism is worked by what is 

 called a " sphincter-muscle." Header, your own eyes are 

 worked by a sphincter-muscle. Stand opposite the look- 

 ing-glass and wink at yourself ; you will then see a sphinc- 

 ter-muscle in operation. 



14. You do not require a sphincter - muscle to your 

 nose, because you are not amphibious. We find, however, 

 that the seal, like the hippopotamus, can close his nose at 

 will by a sphincter-muscle. Go and look at the seal in 

 the Zoological Garden. The valve which works the 

 blow-hole of the whale and porpoise is of an analogous 

 character. Strange to say, we find an animal that is not 

 amphibious which has his nostrils protected by this curi- 

 ous and beautiful valve. But you will, probably, never 

 guess what that animal is. Well, it is the camel the 

 "ship of the desert." In the desert, where the camel 

 lives, there are often "sand-storms," and the Creator has 

 provided the poor camel with this wonderful structure, 

 to save him from suffocation when these terrible sand- 

 storms occur. 



Fran Jo BucTcland. 



