51 
namely, delight ; although the sensible objects have 
no resemblance. No anatomist, no microscopist, 
** Can from the existing what conceive the why:” 
so neither can we guess how various colours and 
forms act on nerves apparently identical in form 
and substance, and chemical properties, and local 
relation, in individuals of different genera and spe- 
cies ; determining the preference of similar to simi- 
lar beings, and their indifference or aversion to dis- 
similars. Thus the lion, in a state of nature, prefers 
his homely Quaker-coloured mate to that of the 
panther or Bengal tiger. The elephant sighs not 
for the giraffe, nor the swarthy hippopotamus for 
the gaily-striped zebra. The dull-coloured brown 
or grey vulture is not attracted by the hyacinthine 
macaw; nor the black by the scarlet ibis; nor the 
common blackbird by the golden oriole; nor the 
black and white by the green woodpecker; nor the 
brown by the emerald creeper; nor the sober vested 
heron by the bright flamingo. Undoubtedly the 
organs of sensation in every genus and every species 
of every class are especially endued with instinctive 
capacities for receiving gratification from such forms 
and colours as are adapted to guide them to their 
appointed destinations. ‘Those who have ever em- 
ployed themselves in colouring maps know the dif- 
ficulty of selecting tints of sufficient number and 
contrast to distinguish numerous subdivisions. . The 
tints of furs, and feathers, and scales, are so diversi- 
fied, so combined, and so contrasted, that ordinary 
E 2 
