394 Darwin, and after Darwin. 
between brilliancy and ornamentation—or between 
colour as merely “heightened,” and as distinctively 
decorative. Yet there is obviously the greatest pos- 
sible difference between these two things. We may 
readily enough admit that a mere heightening of al- 
ready existing coloration is likely enough—-at all 
events in many cases—to accompany a general increase 
of vigour, and therefore that natural selection, by pro- 
moting the latter, may also incidentally promote the 
former, in cases where brilliancy is not a source of 
danger. But clearly this is a widely different thing from 
showing that not only @ general brilliancy of colour, 
but also the particular disposition of colours, in the 
form of ornamental patterns, can thus be accounted 
for by natural selection. Indeed, it is exprc:sly in 
order to account for the occurrence of such ornamental 
patterns that Mr. Darwin constructed his theory of 
sexual selection; and therefore, by thus virtually 
ignoring the only facts which that theory endeavours 
to explain, Mr. Wallace is not really criticizing the 
theory at all. By representing that the theory has to 
do only with brilliancy of colour, as distinguished 
from disposition of colours, he is going off upon a 
false issue which has never really been raised}. Look, 
for example, at a peacock’s tail. No doubt it is suf- 
ficiently brilliant ; but far more remarkable than its 
brilliancy is its elaborate pattern on the one hand, and 
its enormous size on the other. There is no conceiv- 
able reason why mere érzlliancy of colour, as an ac- 
cidental concomitant of general vigour, should have 
run into so extraordinary, so elaborate, and so beau- 
1 Note C. 
