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 w^hich take exclusive charge of 
the eggs and young are more brightly coloured than 
tlie 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 welfare 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- 
Dr. Giinther, since publishing an account of this species in ‘ The 
Fishes of Zanzibar,’ by Col. Playfair, 1866, p. 137, has re-examined the 
specimens, and has given me the above information. 
