MEMOIR. xli 
industrious or nest-building bees, at whose expense they live, in the 
manner of the cuckoo. I found on the banks of the Amazons many 
of these cuckoo bees and flies, which all wore the livery of working 
bees peculiar to the country.” * 
These “ protective resemblances,” or imitation of external ap- 
pearances, are, so far as the end effected is concerned, identical 
with the phenomena of “ protective coloration,” or the adaptation 
of animals in their colours and markings to surrounding objects, 
whereby they are alike concealed from foes and prey. 
Such, to take a few more or less familiar examples, are the sandy 
colours of desert animals ; the white colour of certain arctic animals 
in winter; the sombre colour of nocturnal animals; the green 
plumage of parrots and other tropical birds; the “ mottled blacks 
and browns of woodcocks and snipes which assimilate to the hues 
of dead leaves and grass”; the vertical stripes of the tiger, whose 
haunts are the jungle, with its long yellow grass and its intervals of 
deep shadows ; the waving twig-like form of green snakes suspended 
from branches; the transparency of many marine animals; the 
curious concealment of certain crabs which cover the upper portion 
of their bodies with pieces of seaweed ; the chameleon which, under 
the influence of nervous stimuli received through the eye, contracts 
its pigment-bearing cells, and changes to the colour of the object on 
which it rests; the adaptation of birds to the various colours of the 
foliage amidst which they live; the modifications of the females, 
which are often more mimetic than the males, due to the greater 
perils attending their functions of egg-carrying and hatching; and, 
to end citations from a well-nigh exhaustless list, the protective 
coloration of the eggs themselves. 
Whether there be adaptation of colour of an organism to its 
habitat, whereby it is concealed; or imitation of one species by 
another species, whereby it is rendered conspicuous ; the phenomena 
are so nearly allied in the object attained, which is the securing 
of some advantage,t that the agent in each case may reasonably be 
assumed to be the same. 
“T think,” Bates says, “it will be conceded that all these various 
* Trans. of Linn. Soc., pp. 506 ; 508-9. 
+ For a convenient summary, Grant Allen’s paper on ‘“Mimicry,” in the latest 
edition of the Zzcyclop. Britannica, may be consulted ; and, amongst more recent authori- 
ties, Poulton’s Colours of Animals, Beddard's Animal Coloration, and Hudson's Naturalist 
zn La Plata, ch. viii. 
{ “There is no luxury in Nature. Nothing can arise unless it be useful.”—Weismann’s 
Lssays upon Heredity, vol. ii., pp. 27, 57. 
