ANIMAL LIFE 361 



eat only flesh ; while others eat nothing but plants. Some 

 bring forth their young well developed to a form similar 

 to their own, while others, like the kangaroo, carry their 

 immature young in a pouch on the under side of the body 

 until they are able to care for themselves. 



Animals used as Food. --The lowest forms of animals 

 are not used by man as food. However, these animals 

 are eaten by higher for.ms of animals, and they in turn 

 become the food of man. 



Mammals, birds, fish, mollusks, crustaceans, amphibia, 

 and reptiles are extensively used as food. Among the 

 mammals and birds so used are many game and domestic 

 animals. The number of edible varieties of fish is large. 

 The different varieties of turtles are used as food by nearly 

 all peoples of the earth. 



Oysters and clams are sold in large quantities as food. 

 The oyster industry is one of the most profitable of our 

 fisheries and furnishes employment to a large number of 

 men. The most productive oyster grounds are Long 

 Island Sound, Chesapeake Bay, and Narragansett 

 Bay. 



Among the crustaceans lobsters and crabs are valuable 

 foods. More than twenty million lobsters are taken 

 annually along the north Atlantic coast. 



In addition to the animals which are used directly as 

 food there are many animal products which are so used, 

 such as butter, cheese, and honey. 



Animal Products used for Clothing. Wool is a very 

 valuable animal product (Figure 322). After the wool is 

 cut from the sheep it is cleaned, carded, and woven into 

 cloth. 



The silkworm or caterpillar furnishes all of the real 

 silk that we have. The worm lives upon leaves, prin- 



