136 THE COURTSHIP OF ANIMALS 



fact, as it seems to be the fact, that the excess of males 

 has brought about such a complete reversal in behaviour 

 — the males, instead of the females, requiring the 

 aphrodisiac ? The solution of this problem probably 

 lies with the physiologist. We now know that the 

 problem of sex does not rest merely in the complete 

 development of the primary sexual organs ; we know 

 that fertile unions do not depend merely on the act of 

 pairing, but on the functional activity of those ancillary 

 glands already referred to. And it may well be that 

 some change in the character of the secretions has not 

 only altered the numerical values of the sexes, but 

 reversed the normal role of coloration and behaviour. 

 That is to say, neither polygamy nor polyandry among 

 the lower animals, at any rate, has been brought about 

 or is maintained by the excessive death-rate due to 

 combats for possession of mates, but must be explained 

 as demonstrating inherent changes in the germ-plasm, 

 disturbing the relative proportions of the sexes and 

 correlated with a profound transformation, not only 

 in the behaviour of the sexes during the period of 

 reproductive activity, but also in their physical 

 characteristics. 



The action of the primary sexual glands and of the 

 ancillary glands has, then, to be allowed for in all 

 attempts to interpret behaviour in sexual matters. No 

 less so must this be the case in regard to the development 

 of coloration and other forms of ornament, and the genesis 

 of weapons of offence. But at present we are, in this 

 direction, dealing with an unknown quantity. The 

 recognition of this, however, should not deter us from 

 attempting to solve the riddle of sex from the phenomena 

 which have so far been surveyed. 



