^AY 26 J 906 
May, 1906. The Irish Naturalist, 113 
SOME POINTS REGARDING ANIMAI, COLORATION. 
BY PROFKSSOR RICHARD J. ANDERSON, M.D., M.A. 
Most people who are interested in the relations of things in 
nature know the main facts bearing on mimicry and protective 
coloration. The shapes of animals and plants serve also in 
the same direction, as is well known, and even the character 
of the shading helps to make a curved animal look flat and 
thus escape notice. The following notes will appear not un- 
w^orthy of attention, because of the great importance one 
attaches to the general facts regarding mimicr}^ and coloration. 
Taking conspicuously coloured objects, it is evident that 
the colour is more or less conspicuous, the more or less the 
colour has free room to assert itself by contrast or individual 
assertion, or by the object receiving light from a differently 
coloured surface, provided the colour reflected approaches the 
complementary colour. It is obvious that green and red are 
complementary provided the proper shades be taken. If the 
light be so arranged that the red object receive green rays re- 
flected or rays transmitted, then, very obviously in the latter 
and less so in the former case, the red colour becomes dark. 
Hence a red object may seem dark or even black. If the 
medium be blue or green water, red may be as effective as black. 
Red rays may as effectively disguise a green object as it it 
were black. It is said that great thicJmess of a blue medium 
may give a red character to the transmitted rays. Whatever 
the advantage that may accrue to an animal possessed of con- 
spicuous spots, it seems clear that the spots may be affected 
by the nature of the light through which these spots must 
make themselves felt. If the spots be rendered very dark 
whilst the ground harmonizes with the medium, then these 
spots may be the only clue to the whereabouts of the animal. 
It happens, however, that scent and hearing are both useful 
adjuncts of unquestionable importance in mammals. A hint 
soon becomes sufficient for the trained eye of the bird. 
A 
