1877.] The Colors of Animals and Plants. TIT 
xiv.) does not prove that color determines that choice, while 
much of the strongest evidence is directly opposed to this view. 
All the facts appear to be consistent with the choice depending 
on a variety of male characteristics, with some of which color is 
often correlated. Thus it is the opinion of some of the best ob- 
servers that vigor and liveliness are most attractive, and these 
are, no doubt, usually associated with intensity of color. Again, 
the display of the various ornamental appendages of the male 
during courtship may be attractive; but these appendages, with 
their bright colors or shaded patterns, are due probably to gen- 
eral laws of growth and to that superabundant vitality which we 
have seen to be a cause of color. But there are many considera- 
tions which seem to show that the possession of these ornamental 
appendages and bright colors in the male is not an important 
character functionally, and that it has not been produced by the 
action of voluntary sexual selection. Amid the copious mass of 
facts and opinions collected by Mr. Darwin as to the display of 
color and ornaments by the male birds, there is a total absence of 
any evidence that the females admire or even notice this display. 
The hen, the turkey, and the pea-fowl, go on feeding while the 
male is displaying his finery, and there is reason to believe that 
it is his persistency and energy rather than his beauty which wins 
the day. Again, evidence collected by Mr. Darwin himself 
proves that each bird finds a mate under any circumstances. He 
gives a number of cases of one of a pair of birds being shot, and - 
the survivor being always found paired again almost imme- 
diately. This is sufficiently explained on the assumption that 
the destruction of birds by various causes is continually leaving 
widows and widowers in nearly equal proportions, and thus 
each one finds a fresh mate; and it leads to the conclusion that 
permanently-unpaired birds are very scarce; so that, speaking 
= broadly, ‘every bird finds a mate and breeds. But this would 
almost or quite neutralize any effect of sexual selection of color or 
ornament, since the less highly-colored birds would be at no dis- 
advantage as regards leaving healthy offspring. If, however, 
heightened color is correlated with health and vigor, and these 
healthy and vigorous birds provide best for their young, and 
leave offspring which, being equally healthy and vigorous, can 
best provide for themselves, then natural selection becomes a 
preserver and intensifier of color. Another most important con- 
sideration is, that male butterflies rival or even excel the most 
gorgeous male birds in bright colors and elegant patterns ; and 
