GENERAL SUMMARY AND CONCLUDING REMARKS 



tions ought not to be carried out near the limit of the 

 breeding range of a species, where from other causes un- 

 paired individuals of both sexes may be of not uncommon 

 occurrence. Are we not, however, attaching too great an 

 importance to this imperfection in the first test ? Is it not 

 a question of average, and will not the struggle for territory 

 over a long period of time be sufficient at least to maintain 

 that standard of efficiency which is necessary to ensure the 

 position of the species in the struggle for existence ? I am 

 inclined to think it will, while at the same time recognising 

 the point as a debatable one. 



That the male displays his charms before the female, and 

 that she on her part appreciates the display and exercises a 

 deliberate choice, was at one time deemed possible, but so 

 many and so weighty were the objections which were raised 

 that biologists searched about for a more reasonable inter- 

 pretation. Such an one they found in the modification 

 proposed by Professor G-roos, who, fixing his attention upon 

 the necessity for some effective means of hindering a too 

 liberal yielding to the sexual impulse, saw in the reluctance 

 of the female a barrier which might require all the so-called 

 arts of courtship for its removal. Some criticisms bearing 

 directly upon this aspect of the problem will be found in the 

 life of the Marsh Warbler. Serious objections seem to me to 

 stand in the way of its acceptance, but nevertheless it is the 

 only modification of the theory which can in any way be made 

 to correspond with the facts. 



More space is devoted in the foregoing pages to emotional 

 manifestation than to any other aspect of behaviour. Perhaps 

 it is as well that it should be so, for we know little enough of 

 the constitution of emotion or of the part it has to play in 

 organic life, and only by minute observation, careful analysis, 

 and comparison, can we hope to make any headway in the 

 direction of a more complete understanding of the objective 

 aspect of the subject. That each instinct has its correspond- 

 ing emotion, as suggested by Dr. McDougall, seems to be true. 



7 



