ECONOMIC ZOOLOGY 509 



Species of gasteropods (snails) are prized in certain parts of the 

 world. It is believed that the mussels were an important 

 article of food to some tribes of North American Indians, and to 

 some of the peoples of the old world when they were in a corre- 

 sponding stage of development. Among the arthropods the 

 lobster comes first in importance, although it has been fished to 

 such an extent that the output is rapidly diminishing and the 

 size of specimens on the market is steadily decreasing. Cray- 

 fish, shrimps, prawns, and crabs are also used to some extent. 

 The great class of insects furnishes only the honey of the honey- 

 bee. Locusts have sometimes been used as a famine ration, and 

 among some primitive tribes normally. 



Every class of vertebrates furnishes food species. The 

 amphibians and the reptiles stand lowest in this respect. The 

 frogs and turtles and a few lizards are their only edible repre- 

 sentatives. The fishes, the birds, and the mammals furnish 

 the staple meat foods. A very large per cent, of the fishes are 

 recognized as edible. Many species of the sharks, even, are 

 prized although they are actively carnivorous, and the car- 

 nivorous animals have usually not been regarded popularly as 

 good to eat. Numerous species of birds have been eaten, but 

 those that rank as of real importance belong chiefly to the 

 Gallinffi, the Columbse, and the Anseres. These three classes of 

 birds supply to man hundreds of millions of dollars worth of his 

 choicest food annually. 



Among the mammals many species have been eaten, but 

 the great division of ruminants and the swine furnish the 

 bulk of the meat food now used by the human race. The 

 horse is not without importance in this respect although not 

 often eaten, in this country, knowingly. Among uncivilized 

 people, before the domestication and improvement of the ox, the 

 sheep, and the hog, this division (ruminants) still furnished the 

 chief wild game animals. Besides meat they furnish milk, 

 butter, and cheese. In the far north the walrus, the bear, and 

 the reindeer take the place of these well-known forms. 



502. Animals as a Source of Clothing for Man. — In the 

 case of primitive man the skins and furs of animals were the 

 sole source of clothing and one of the means of building arid 



