or BKI.KDING H.\\(,i Lfl 



some hundreds of miles or merely embr<i< 

 parish or so in extent, and that purpose is the 

 acquirement of a territory suitable for rearing 

 offspring. They are thus directly related to the 

 territory, and the question arises as to whether 

 their origin may not be traced to such related- 

 ness. So long as we fix our attention solely 

 upon the magnitude of the distance traversed 

 the suggestion may seem a fanciful one. Never- 

 theless, if the battles between males of the 

 same species are directly related to the occupa- 

 tion of a position suitable for breeding purposes, 

 if those which occur between males of closely 

 related forms can be traced to a similar source, 

 if the females take their share in the defence 

 of the ground that is occupied, if, in short, the 

 competition is as severe as I believe it to be, 

 and is wholly responsible for the strife which 

 is prevalent at the commencement of the 

 breeding season then such competition must 

 have introduced profound modifications in the 

 distribution of species ; it must have even 

 influenced the question of the survival of 

 certain forms and the elimination of others ; 

 and since the powers of locomotion of a bird 

 are so highly developed it must have led to 

 an extension of breeding range, limited only 

 by unfavourable conditions of existence. 



