Chap. XV. 
SEXUALLY-LIMITED INHEEITANCE. 
155 
lias been discussed in some very interesting papers by 
Mr. Wallace,^ who believes that in almost all cases the 
successive variations tended at first to be transmitted 
equally to both sexes ; but that the female was saved, 
through natural selection, from acquiring the conspicu- 
ous colours of the male, owing to the danger which she 
would thus have incurred during incubation. 
This view necessitates a tedious discussion on a 
difficult point, namely ivhether the transmission of a 
character, which is at first inherited by both sexes, can 
be subsequently limited in its transmission, by means 
of selection, to one sex alone. We must bear in mind, 
as shewn in the preliminary chapter on sexual selec- 
tion, that characters which are limited in their de- 
velopment to one sex are always latent in the other. 
An imaginary illustration will best aid us in seeing 
the difficulty of the case : we may suppose that a 
fancier wished to make a breed of pigeons, in which 
the males alone should be coloured of a pale blue, 
whilst the females retained their former slaty tint. As 
with pigeons characters of all kinds are usually trans- 
mitted to both sexes equally, the fancier would have 
to try to convert this latter form of inheritance into 
sexually-limited transmission. All that he could do 
would be to persevere in selecting every male pigeon 
which was in the least degree of a paler blue ; and the 
natural result of this process, if steadily carried on for 
a long time, and if the pale variations were strongly 
inherited or often recurred, would be to make his whole 
stock of a lighter blue. But our fancier would be com- 
pelled to match, generation after generation, his pale 
blue males with slaty females, for he wishes to keep j^he 
^ ‘Westminster Eeview,’ July, 1867. ‘Journal of Travel,’ vol. i. 
1868, p. 73. 
