78 SEX 



by the males in the water. In the viviparous 

 Cyprinodonts, on the other hand, where there 

 is internal fertilisation and economy of sperm- 

 material, the males show both permanent and 

 periodic distinguishing features (see Fig. 14). 

 In his critique of this " surplusage theory," 

 Kammerer indicates some serious, and indeed 

 fatal, objections. (1) It may explain how the 

 male has a good deal to spare on decoration, 

 but it sheds no light on the specific line that 

 his disposal of the surplus takes a mane for 

 the lion and antlers for the stag. (2) It is 

 easy to pick out cases that suit the theory, 

 but what of the broad fact that in hundreds 

 of cases among birds and mammals, reptiles 

 and insects, the two sexes are equal in size, 

 equal in numbers, and uniform in appearance, 

 although the expenditure on the male's side 

 remains very much less than on the female's ? 

 (3) The female's reproduction is more ex- 

 pensive, yet it is the female that tends to 

 fatten. And why is it that when her repro- 

 ductive expenditure is over, her accessory 

 sex-characters do not improve (except in 

 rare cases), but become less marked than 

 ever ? (4) There are many cases where the 

 male has to fertilise the eggs of many females, 

 and where he has no masculine peculiarities, 

 which is what the theory would suggest. But 

 there are also many cases of a similar sort, 

 where the polygamous male, like peacock, 

 pheasant, stag, bull, sea-lion, shows an 

 exuberance of masculine features. Indeed 

 it may be argued that increased sexual 

 function in the male tends to increase the 

 masculine features, and vice versa. 



