PRACTICAL ZOOLOGY 



CHAPTER I 

 WHERE ANIMALS LIVE 



IF we compare the structures of our bodies, the food we eat, 

 the way we move from place to place, and our various other 

 activities with those of the apes, such as the gorilla, chimpanzee, 

 and orang-utan, we become aware of many similarities. If we 

 continue the comparison with other animals, for example, cattle, 

 sheep, horses, dogs, cats, etc., we realize that they possess struc- 

 tures and carry on activities which resemble in a general way 

 those of the apes and man. Likewise the birds, snakes, turtles, 

 frogs, and fish have many peculiarities in common with other 

 animals and with us. 



Besides these animals, every one is more or less familiar with 

 many of what we call the " lower animals," especially insects, 

 snails, oysters, earthworms, starfishes, tapeworms, and jellyfishes. 

 All of these animals must be able to live amid their surroundings ; 

 that is, in their natural habitat, and to reproduce others to con- 

 tinue the race after they are dead so that their kind may not 

 disappear entirely from the earth. In order to live, human be- 

 ings, as well as all the other animals, need certain things. The 

 most important needs for the maintenance of life are food, 

 water, air (oxygen), p r .ection, and an opportunity to repro- 

 duce. These needs are satisfied by different kinds of animals 

 in different ways, and the variety of structures employed for 

 satisfying these needs and the methods used seems almost infinite. 



We are accustomed to think of other animals as living on land 



