[October, 
5 7 6 
On the Distribution of Colours 
exert on us a contagious adtion, on account of the in- 
stinctive struggle of the ego against the reflex adtion which 
tends to produce them. 
II. ON THE DISTRIBUTION OF COLOURS 
IN THE ANIMAL WORLD. 
IGNOR LORENZO CAMERANO has been for some 
time engaged with the study of the distribution of 
colours in the animal kingdom. He has communi- 
cated his results to the Academy of Turin, and has given an 
abstradt in the “ Zoologischer Anzeiger ” for July last. 
He first examines the respective frequency of occurrence 
of different colours in the animal world, and arranges them 
in the following order: — i, Brown; 2, black; 3, yellow, 
grey, and white ; 4, red : 5, green ; 6, blue ; and 7, violet, 
the rarest. It will be observed that Signor Camerano ranks 
here black and white, and their mixture grey, as colours. 
These colours are, however, by no means equally distri- 
buted in the main groups of the animal kingdom. Black, 
brown, and grey, we are told, are more abundant — relatively 
of course — among the vertebrates than among arthropods. 
Red and yellow, on the other hand, are more frequent in the 
evertebrate animals. Green, also, is frequent among the 
lower animals, with the exception of the molluscs, but is 
also abundant in vertebrates, though, it might have been 
added, not among mammals. Violet and blue are the rarest 
colours, especially violet, though we meet with it in almost 
all animal groups. White is very irregularly distributed, 
but occurs most frequently among aquatic forms. 
The colours of animals are, on the whole, direCIly related 
to the medium which they inhabit. 
Parasites have less decided and less manifold colours than 
those which lead an independent existence. 
Aquatic animals have in general more equable and less 
intense colours than terrestrial forms. Pelagic species have 
(To be continued). 
