206 SEXUAL DIMORPHISM 



first left his partner and erected his fins, etc., at the third. 

 After a few demonstrations the first darted above the third, 

 striking the first dorsal of the latter, which then fled, although 

 no injury whatever was inflicted. A similar attack was 

 observed on another occasion, but the defeat of the third male 

 did not prevent him pairing successfully with the female 

 alternately with his conqueror. It is thus evident enough 

 that the peculiarities of the male cannot be ascribed to the 

 selection of those individuals which possess them in greatest 

 perfection. It is true that the observer in this case does not 

 mention any difference in the special characters among the 

 three males concerned, but he does note that the third male, 

 which was smaller than 1 and 2, was equally successful in 

 pairing. Mr. Holt "imagines" that the demonstrations of 

 large, fully differentiated males would have the effect of 

 driving off sexually mature specimens which were not so large, 

 and whose insignia were not so fully developed. But he has 

 no observations to support this belief, and if it were correct 

 it would only be a case of seniores priores, the smaller speci- 

 mens would become fully developed and pair with the females 

 when their time came. 



Males in the mature condition appear to be much more 

 abundant than females. In one case Mr. Holt found that of 

 the whole number of dragonets caught by a trawler, 95 were 

 males and 21 females, and he has observed an excess of males 

 in the course of his own trawling operations. This fact is 

 worth noting in comparison with the numerical relations 

 between the sexes in polygamous birds and other animals. 

 In one case superiority in size, and special adornment, both of 

 colour and structure, is found when each male has several 

 wives ; in the other, when there are several males to one 

 female. The fact that is common to both cases is, that the 

 male habitually makes particular gestures and movements 

 under the influence of sexual excitement. 



