REPRODUCTION AND SEX 515 



by its ardent importunity so stimulate the female that she con- 

 descends first of all to be interested and then perhaps to reciprocate. 

 Some males will be more successful than others; but Mr. Bristowe 

 doubts whether sexual selection in Darwin's sense can be con- 

 vincingly proved. It seems to us, however, that his observations 

 afford sufficient basis for Darwin's theory, as it would be re-stated 

 to-day. 



There seems to be good sense in the "recognition and excitation" 

 theory; but we must not think of the amorous male spider as an 

 intelligent homunculus, nor of the coy female as "recognising" him 

 in our sense of the word. For both sexes are dominated by hereditary 

 "chain-instincts" which prompt them to follow unthinkingly a 

 certain routine of behaviour. From what we know of spiders we feel 

 bound to say "unthinkingly"; yet we have an open mind as to the 

 degree to which the enregistered behaviour-promptings are suffused 

 with awareness and backed by endeavour. We believe, though we 

 cannot prove, that some awareness and some endeavour accompany 

 most of the complex instincts. They are miles away from intelli- 

 gence ; but in origin and in actuality they are not to be dissected off 

 from mind. 



It is well known that some male spiders at the courting-time will 

 fight protracted duels without hurting one another. They stop 

 when they are tired, usually without drawing blood. We agree with 

 Bristowe that these combats have been described too generously, 

 for it is very unlikely that they express rivalry or jealousy or any- 

 thing very subtle. In all probability they express the excitement 

 of disappointed or frustrated males. A lusty male spider will some- 

 times fight with his own image in a mirror — a quaintly inverted 

 Narcissism. 



What is clearly indicated by the behaviour of courting spiders is 

 the frequent subtlety and specificity of the ways in which the 

 amorous male brings himself to the notice of the female and excites 

 her interest and her sympathy. The probability is that the type of 

 male most successful in this art of courtship will have most success 

 in actual reproduction and parentage, and will thus be favoured by 

 selection — both natural and sexual. 



HOWARD'S STUDIES ON SEX-BEHAVIOUR IN BIRDS.— 



The study of sex-behaviour in birds has been deepened by Eliot 

 Howard's patient and critical observations, and we propose to give 

 a short account of his important Introduction to the Study of Bird 

 Behaviour (1929). The characteristic of the book is that it studies 

 the behaviour of birds as living wholes and in their natural environ- 

 ments. "One reaction in itself is neither more nor less important 

 than another; each forms a portion of the environment for others; 

 each is sensitive to the modification of others — they form a con- 



