96 ZOOLOGY 



in precise ways to particular stimuli, having little "free- 

 dom of the will." This dominance of instinct makes 

 them equally reliable as workers, whether in their own 

 nests or in those of other ants. Hence it has been pos- 

 sible for certain kinds to establish a system of slavery, 

 by stealing the immature forms of other species and 

 raising them to maturity. The "slaves," thus ob- 

 tained, work quite as well in the colonies of their ab- 

 ductors as they would in their own. The peculiar ant 

 called Polyergus, though a great fighter, has to depend 

 for food entirely on its slaves. There is nothing but 

 instinct to prevent the latter from running away and 

 leaving their masters to starve, but they never do so. 

 They are enslaved by their own natures. 



6. Passing up through the lower vertebrates and 

 mammals, in the line leading toward man, we find very 

 little socialization ; practically none until we come to 

 the monkeys, which live in bands. 1 Had man never 

 appeared, there would be no reason for connecting the 

 highest types of life with relative perfection of social 

 organization. Some intelligent being who might be 

 discussing the matter can be thought of as saying : 

 "Extreme socialization is very well for insects, such as 

 ants, but is quite unsuited for vertebrates, especially 

 the higher types ; a loose form of organization, in bands 

 or flocks, is often advantageous, but all experience is 

 against carrying the principle to extremes." It could 

 not be argued, however, that the method failed among 

 the ants, for these are the most successful of insects, and 

 literally own the earth wherever it is possible for them 

 to live. 



1 Birds, wolves, prairie dogs, and other vertebrates occur in groups or 

 flocks, but they do not form highly developed societies, nor do they belong to 

 the series giving rise to man and his relatives, except in the very general 

 sense of being vertebrates or mammals. 



