14 INTRODUCTION, 



assistance of whatever facts I can command. 

 I shall do so not only for the purposes of the 

 theory, but because one so often finds the 

 more important features of sexual behaviour 

 regarded as so many distinct phenomena requir- 

 ing separate treatment, whereas they are mutually 

 dependent, and follow one another in ordered 

 sequence. I spoke of the process as a series 

 of relationships. Some of these relationships 

 have, already been touched upon ; others will 

 become apparent if we consider for a moment 

 the purposes for which the territory has been 

 evolved. Indirectly its purpose is that of the 

 whole process, the rearing of offspring. But 

 inasmuch as a certain measure of success could 

 be attained, and that perhaps often, without all 

 the complications introduced by the territory, 

 there are manifestly advantages to be gained 

 by its inclusion in the scheme. The difficulties 

 which beset the path of reproduction are by no 

 means always the same— all manner of adjust- 

 ments have 1^0 be made to suit the needs of 

 different species. There are direct relationships, 

 such as we have been speaking of, which are 

 essential to the every- day working of the 

 process, and others which are indirect, though 

 none the less important for they must have 

 exercised an influence throughout the ages. 

 These latter are furnished by the physical — the 

 inorganic world, by climate, by the supply of 

 the particular kind of breeding stations, by the 

 scarcity or abundance of the necessary food 

 and by the relative position of the food supply 



