346 The Descent of Man. Pakt li. 



protected or unprotected by the parents, has had little or no 

 influence on the differences in colour between the sexes. It is 

 further manifest, in all the cases in which the males take 

 exclusive charge of the nests and young, that the destruction 

 of the biighter-co]oured males would be far more influential on 

 the character of the race, than the destruction of the brighter- 

 coloured females ; for the death of the male during the period of 

 incubation or nursing would entail the death of the young, so 

 that they could not inherit his peculiarities ; yet, in many of 

 these very cases the males are more conspicuously coloured than 

 the females. 



In most of the Lophobranchii (Pipe-fish, Hippocampi, &c.) 

 the males have either marsupial sacks or hemispherical de- 

 pressions on the abdomen, in which the ova laid by the female 

 are hatched. The males also shew great attachment to their 

 young. 89 The sexes do not commonly differ much in colour; 

 but Dr. Glinther believes that the male Hippocampi are rather 

 brighter than the females. The genus Solenostoma, however, 

 offers a curious exceptional case, 40 for the female is much more 

 vividly-coloured and spotted than the male, and she alone has a 

 marsupial sack and hatches the eggs; so that the female of 

 Solenostoma differs from all the other Lophobranchii in this 

 latter respect, and from almost all other fishes, in being more 

 brightly-coloured than the male. It is improbable that this 

 remarkable double inversion of character in the female should 

 be an accidental coincidence. As the males of several fishes, 

 which take exclusive charge of the eggs and young, are more 

 brightly coloured than the females, and as here the female Sole- 

 nostoma takes the same charge and is brighter than the male, it- 

 might be argued that the conspicuous colours of that sex which 

 is the more important of the two for the welfare of the offspring, 

 must be in some manner protective. But from the large number 

 of fishes, of which the males are either permanently or period- 

 ically brighter than the females, but whose life is not at all 

 more important for the welfare of the species than that of the 

 female, this view can hardly be maintained. When we treat 

 of birds we shall meet with analogous cases, where there has 

 been a complete inversion of the usual attributes of the two 

 sexes, and we shall then give what appears to be the probable 

 explanation, namely, that the males have selected the more 

 attractive females, instead of the latter having selected, in 



» Yarrell. < Hist, of British Fishes of Zanzibar,' by Col. Playfair, 



Fishes,' vol. i'i. 1836, pp. 329, 338. 1866, p. 137, has re-examined ths 



** Dr. Giinther, since publishing specimens, and has given me th« 



ttB account of this species in 'The above information. 



