318 THE STRUCTURE AND LIFE OF BIRDS cuwap. 
produced, and if the sexes show a difference in adorn- 
ment, it is almost always the male that is more 
brightly coloured. In many butterflies, and in some 
fishes and crustaceans, there are such differences. 
Among sea-urchins and starfish there is thought to be 
in some cases a superiority in point of colour in the 
male over the female.! It is very important, if we 
are to come to a right conclusion upon this question, 
that all the facts should be considered, and one of the 
most important facts is this which Professor Geddes has 
emphasized, that in many of the lower animals, and as 
a rule among the higher, we find the male possessing 
some superior adornment. Here we have an undoubted 
tendency, however we may seek to account for it. 
But to explain the Peacock’s enormous plumes we 
require something further. We want to know why 
the regulating law of the Survival of the Fittest has 
not reduced their growth. If we ask why a Peacock 
is encumbered by a train that may easily lose him 
his life, itis no answer to be told that in a certain 
species of crustacean (Sguzlla stylifera for instance) 
the male is rather more brilliantly coloured than the 
female. 
Mr. Stolzmann has, I believe, supplied the clue to 
this puzzle. According to him it is advantageous to 
the species that the number of cock-birds should be 
kept down, and their grand plumage helps towards 
this end. This is an extension of Dr. Wallace’s view 
that it is the female which mainly needs protection. 
Mr. Stolzmann maintains that the cock-bird in many 
species not only needs no protection, but that it is 
1 See Beddard’s Animal Coloration, p. 255. 
