1 878.] 
Doctrine of Development. 
459 
fundamentally sound ; and that, although we now know 
that colour has uses in Nature that they little dreamt of, 
yet the relation of those colours— -or rather of the various 
rays of light — to our senses and emotions may not be 
another, and perhaps more important, use which they sub- 
serve in the great system of the Universe.” Elsewhere he 
remarks that “ the extreme diversities and exquisite beauties 
of colour seem out of proportion to the causes that are 
supposed to have produced them, or to the physical needs 
to which they minister.” And again : — “ It is hardly con- 
ceivable that the material uses of colour to animals and to 
ourselves required such very distinct and powerfully con- 
trasted sensations ; and it is still less conceivable that a 
sense of delight in colur, per se, should have been necessary 
for our utilisation of it. The emotions excited by colour 
and by music alike seem to rise above the level of a world 
constructed on purely utilitarian principles.” Yet at the 
same time he declares, and truly, that he has shown reasons 
for believing that the presence of colour in some of its 
infinitely-varied modifications is more probable than its 
absence, and that variation of colour is an almost necessary 
concomitant of variation in structure, development, and 
growth. On the colour-sense in animals he remarks “ that 
the higher vertebrates, and even some inseCts, distinguish 
what are to us diversities of colour, hut this by no means 
proves that their sensations of colour bear any resemblance 
to our own. An insect’s capacity to distinguish red from 
blue or yellow may be (and probably is) due to perceptions 
of a totally distinct nature, and quite unaccompanied by 
any of that sense of enjoyment, or even of radical distinct- 
ness, which pure colours excite in us. Mammalia and 
birds, whose structure and emotions are so similar to our 
own, do probably receive somewhat similar impressions of 
colour, but we have no evidence to show that they experience 
pleasurable emotions from colour itself when not associated 
with the satisfaction of their wants or the gratification of 
their passions.” 
There is here, it appears to us, some little assumption. 
We have certainly no evidence that birds and beasts expe- 
rience pleasurable emotions from colour alone. But what 
evidence have we to the contrary ? The capacity of an 
inseCt to distinguish colours may be accompanied by any of 
that sense of enjoyment which pure colours excite in us. 
But why should we pronounce this probable ? Still more, 
why should its power to distinguish colours be unaccompanied 
by a sense of radical distinctness ? Quite admitting that the 
