400 BOAED OF AGRICULTURE. 



6. By the structure of complicated homes, characteristic 

 of different species. 



7. By the peculiar impulses of the young by which they 

 are at once brought into proper relations to their parents and 

 the world. The young of our hoof-bearing animals, for in- 

 stance, must seek the udder for themselves, as the mother 

 cannot aid them. 



8. By the change of impulse and habit in different stages 

 of existence of the same individual, for its own advantage ; 

 as among insects. 



9. By the impulses and actions of animals demanding cer- 

 tain changes in other beings to complete their work ; as the 

 formation of oak-galls to complete the work of the insect in 

 providing for its young. 



10. By the many cases in which the instinctive act exactly 

 supplants structure and function ; as the honey-bee has the 

 function in the wings of its body of secreting wax, and in its 

 mandibles, instruments for forming a cell. Instinct prompts 

 the bee to use the instrument and the product of the function 

 to construct its comb. 



11. By the inter-action of the instinct of the mother and 

 that of the young ; as when the fowl gives the note of warn- 

 ing, and the young instantly scatter from her and hide, 

 because she cannot protect them. 



12. By those cases, as among fishes and many insects, 

 where the young never see the parent, never have an oppor- 

 tunity to learn from one of their kind ; and yet instinctive 

 impulse directs them in the same way, and in the best way, 

 in all the exigencies of life. 



A careful study of the subject shows the great difficulty of 

 distinguishing instinctive action from reflex, on the one hand, 

 and from intelligent on the other. This difficulty arises from 

 the fact that the different kinds of acts are often alike in their 

 results ; and in the chief field of their manifestations, that is, 

 among the lower animals, we have no means of determining 

 their nature, but observation as to the method and the con- 

 dition of the action. Whether there is among them conscious 

 relation of the actor to the act, it is impossible for us to 

 learn except by inference. Reflex and instinctive acts are 

 both in the same line, for the benefit of the individual in 



