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ANIMAL COLOURING 
sex by a long course of discerning feminine selection, 
it has an unconscious irony. Going quite outside the 
merits of the male sex per se, Mr. Stoltzmann weighs 
its worth in view of the survival of a species. So 
considered, an excess of males is an evil, which the 
law of natural selection is under obligations to 
remedy . 1 The tendency of Nature is to produce a 
superabundance of males, observations on the origin 
of sex having shown that the percentage of male 
birds among birds is greater than that of females. 
Further inquiries into the influence of nutrition on 
sex go to show that badly-nourished eggs produce 
males, while well-nourished eggs produce females ; 
and scarcity of food is a more common condition 
than its abundance. The fine feathers which “make 
fine birds” have therefore been given to the males 
with a view to exposing them to the attacks of their 
enemies, and so reducing their numbers, always — be 
it observed — in accordance with the law of the 
survival of the fittest, but by a curiously different 
line of argument from that which lent its weight to 
the theory of sexual selection. Probably neither the 
one nor the other should stand alone ; nor is this result 
to be feared. Bigotry seems almost unknown to the 
spirit of the natural history research of to-day ; the only 
danger of the open mind of its followers is in the con- 
structive ingenuity of theory which it seems to foster. 
1 The bad result of an excess of males is perhaps best ascer- 
tained in the case of grouse moors. See Mr. A. Stuart Wortley’s 
remarks upon this in The Grouse (Fur and Feathers Series, 
Longmans, Green & Co.). 
