138 Instinct, 



by birds for the benefit of their fellows, and safety 

 thus secured to the flock, we began to see the 

 community system, which prevails extensively in 

 the animal kingdom and gives rise to very distinct 

 and complex manifestations of Instinct. 



When the community system becomes promi- 

 nent, a single animal, or a single pair, often be- 

 comes a very imperfect representative of the spe- 

 cies, if we wish to study the whole work of Instinct. 

 Individuality is lost in the machinery of the com- 

 munity. And so far does this system prevail among 

 some species, that a single male and female cannot 

 possibly care for their young. In more than one 

 case the species could not possibly exist without the 

 aid of individuals from other species. In such cases, 

 the dependent species have an Instinct to secure 

 the services of other laborers and thus supplement 

 their own defects. 



In the case of the Cow-bird, already referred to, 

 the species would perish were it not for the work 

 of other birds in hatching and feeding the young 

 Cow-bird. But so far as we can judge, this defect- 

 ive care of the Cow-bird for her offspring arises en- 

 tirely from the action of its Instinct, — defective ac- 

 tion when taken by itself, but effective when we 

 consider its relation to the Instinct of other birds 

 whose work it secures. We see nothing in the or- 

 ganization of the bird to prevent it from nesting 

 and rearing its brood like other birds. But lower 

 in the scale of being, we find three kinds of animals 

 belonging to the same species — the males, females 

 and neuters — all needful for carrying on the work 



