18 THE COURTSHIP OF ANIMALS 



Lloyd Morgan, who was one of the first to take up 

 this difficult line of investigation, and to Professor 

 Groos. Their researches have shown that there can 

 be no doubt but that the emotions have played and are 

 playing an important part in the phenomena we are 

 striving to analyse. Sexual selection, in short, is con- 

 cerned not merely with the evolution of the physical 

 characters of the body, but also, and no less, with 

 the psychological attributes thereof. Many new and 

 extremely valuable facts in this regard have been brought 

 to light by Mr. H. Eliot Howard in the course of his 

 remarkable studies on our native warblers. Not until 

 the psychology of sex in the lower orders of creation has 

 been further investigated shall we have a properly 

 balanced account of the part played by sexual selection 

 in the scheme of evolution. 



By now it will have become apparent that the study 

 of the " Courtship " of animals is one of alluring interest 

 and full of pitfalls for the unwary. And this because of 

 the apparent difficulty in drawing any hard-and-fast line 

 between the part played by " Natural '* and the part 

 played by " Sexual " Selection, at any rate in some cases. 



To this aspect of the theme Professor Lloyd Morgan 

 has drawn particular attention. " It is difficult," he 

 remarks, " to accept the view that individual choice 

 has played no part where the sexual instincts are con- 

 cerned. But supposing that it has played its part . . . 

 the effects will be wrought into the congenital tissue of 

 the race if, and only if, there are certain individuals 

 which, through failure to elicit the pairing response, 

 die unmated. Is preferential mating, supposing it to 

 occur, carried to such a degree that some individuals 

 fail to secure a mate ? That is the question. If so. 



