22 SEXUAL SELECTION. Part II. 



however, offers a very curious exceptional case,^^ 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 Solenostoma takes 

 the same charge and is brighter than the male, it might 

 be argued that the conspicuous colours of the sex which 

 is the most important of the two for the welfare of the 

 offspring must serve, in some manner, as a protection. 

 But from the multitude of fishes, the males of which 

 are either permanently or periodically brighter than 

 the females, but whose life is not at all more important 

 than that of the female for the Avelfare of the species, 

 this view can hardly be maintained. When we treat of 

 birds we shall meet with analogous cases in which 

 there has been a complete inversion of the usual attri- 

 butes 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 accordance with 

 the usual rule throughout the animal kingdom, the more 

 attractive males. 



On the whole we may conclude, that with most fishes, 

 in which the sexes differ in colour or in other orna- 



s** Dr. Giiuther, since publishing an account of this species in ' The 

 Fishes of Zanzibar,' by Col. Playfuir, I8G6, p. 137, has re-examined the 

 specimens, and has given me the above information. 



