SEXUAL SELECTION 445 



To return to our more immediate subject. The case 

 stands thus: female fishes, as far as I can learn, never 

 willingly spawn except in the presence of the males; and 

 the males never fertilize the ova except in the presence 

 of the females. The males fight for the possession of the 

 females. In many species, the males while young resemble 

 the females in color; but 'when adult become much more 

 brilliant, and retain their colors throughout life. In other 

 species the males become brighter than the females and 

 otherwise more highly ornamented, only during the season 

 of love. The males sedulously court the females, and in 

 one case, as we have seen, take pains in displaying their 

 beauty before them. Can it be believed that they would 

 thus act to no purpose during their courtship? And this 

 would be the case unless the females exert some choice and 

 select those males which please or excite them most. If the 

 female exerts such choice, all the above facts on the orna- 

 mentation of the males become at once intelligible by the 

 aid of sexual selection. 



We have next to inquire whether this view of the bright 

 colors of certain male fishes having been acquired through 

 sexual selection can, through the law of the equal transmis- 

 sion of characters to both sexes, be extended to those groups 

 in which the males and females are brilliant in the same, or 

 nearly the same, degree and manner. In such a genus as 

 Labrus, which includes some of the most splendid fishes 

 in the world — for instance, the Peacock Labrus {L. pavo), 

 described," with pardonable exaggeration, as formed of 

 polished scales of gold, inerusti-ng lapis-lazuli, rubies, sap- 

 phires, emeralds, and amethysts — we may, with much prob- 

 ability, accept this belief; for we have seen that the sexes 

 in at least one species of the genus difEer greatly in color. 

 With some fishes, as with many of the lowest animals, splen- 

 did colors may be the direct result of the nature of their tis- 

 sues and of the surrounding conditions, without the aid of 



^ Bory de Saint Tincent, in "Diet. Class. d'Hlst. Nat.," torn, ix., 1826, 

 p. 151. 



