520 BIOLOGY AND HUMAN LIFE 



with some success ; but these animals are not yet domesticated, 

 and they are not yet a part of the breeder's problem. 



Among the birds the common hen is the most important, 

 ducks and geese and turkeys coming next. The pea fowl, the 

 guinea fowl, and other species have been kept in flocks ; parrots, 

 canaries, and others have been kept as pets ; and attempts have 

 been made to domesticate many "wild" species. 



Fish culture has developed rapidly in modern times, but out- 

 side of the goldfish and a few other forms that are kept in jars 

 we can hardly call any of them domesticated. Brooks and lakes 

 have been stocked with young fry or with fertilized eggs, and 

 bodies of water have been protected so as to give the fish a 

 chance to multiply, but they have not been cared for in the same 

 way as our goats and cows. A few invertebrates fall under the 

 care of the fish-culture activities of the Bureau of Fisheries — 

 oysters, mussels, and lobsters, for example ; but these are not, 

 strictly speaking, cultivated as are chickens and dogs. 



Among the insects the honeybee and the silkworm are truly 

 domesticated animals. There are many varieties in both species, 

 and close attention is given to the conditions of their living and 

 to protection from dangers or enemies. 



The animals that man has attached to himself, while they 

 differ in many ways from each other, must have certain quali- 

 ties that make domestication possible. The dog, for example, 

 although related to the wolf, has a disposition that permits him 

 to learn to live in a way that will make him acceptable. The 

 horse, the cow, the sheep, and the pig submit to man's mastery. 

 It is possible, however, that many other species that are not now 

 domesticated could be made to live under our control if we 

 caught them young and used our skill in adjusting them to our 

 needs; for all the wild animals in the menagerie and in the 

 zoological gardens show a great deal of adjustment to life under 

 artificial conditions. Moreover, in Africa and Asia there are 

 still species of wild horses that, when caught young and broken 

 to the saddle or harness, are just as serviceable as those born 

 and brought up on farms. 



