EFFECT OF THE GREGARIOUS INSTINCT 293 



to procreate their kind and maintain the 

 tradition. Let it once be granted that there 

 is an innate capacity to retain in later phases 

 of routine the experience gained in earUer 

 phases, and it is difficult to see how traditional 

 guidance can be refused recognition as a factor 

 in the developing situation. But only a factor, 

 and by no means the most important one ; for 

 observation has shown that the young are 

 capable of performing the return journey 

 without guidance. Something therefore is 

 inherited, some impulse which comes into 

 functional activity at a specified time, and leads 

 the bird to set forth in a given direction. 



There are no grounds for supposing that 

 the experience of one generation forms any 

 part of the hereditary equipment of subsequent 

 generations. In what direction then are we to 

 look for the congenital factor ? What is given 

 is an inherited tendency to co-operation and 

 mutual help, and an innate capacity to make 

 use of the results of experience. The inherited 

 tendency, as we have seen, leads on the one 

 hand to the formation of new areas of associa- 

 tion, whilst on the other, since it is the means 

 of bringing isolated individuals into contact, 

 it leads to experience being handed on from 

 generation to generation, which, in its turn, 

 results in a certain amount of backward move- 

 ment along the line of expansion. It forms 

 part of the hereditary equipment of many 

 species, and is serviceable in promoting the 

 welfare of the individual. Moreover, there is 



U 2 



