26 DISPOSITION TO SECURE A TERRITORY 



necessary prelude to the completion of the 

 sexual act, and to which close companionship 

 would tend to impart a stimulus. 



In thus speaking, however, we assume that 

 the revival of the sexual instinct in the migratory 

 male is coincident in time with its return to the 

 breeding quarters ; and we do so because the 

 act of migrating is believed to be the first step 

 in the breeding process. But it is well to bear in 

 mind just how much of this assumption is based 

 upon fact, and how much is due to questionable 

 inference. All that can be definitely asserted is 

 this, that appropriate dissection reveals in most 

 of the migrants, upon arrival at their destination, 

 unquestionable evidence of seasonal increase in 

 the size of the sexual organs. Beyond this there 

 is nothing to go upon. Yet if the term " sexual 

 instinct" is held to comprise the whole series of 

 complex relationships which are manifest to us 

 in numerous and specialised modes of behaviour, 

 which ultimately lead to reproduction, and which 

 have gradually become interwoven in the tissue 

 of the race, there can be little doubt that the 

 assumption is a reasonable one. To some, the 

 term may recall the fierce conflicts which are 

 characteristic of the season ; to others, emotional 

 response ; to not a few, perhaps, the actual 

 discharge of the sexual function — all of these, it 

 is true, are different aspects of the one instinct ; 

 but at the same time each one marks a stage in 

 the process, and the different stages follow one 

 another in ordered sequence. However, we are 

 not concerned at the moment with the term in 



