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could explain that law so well as‘a few simple words of the arent 
naturalist himself, and which I will quote: “Nature * * 
cares nothing tor appearances, except in so far as they are eae 
to any being. She can act on every internal organ—on 
every shade of constitutional difference—on the whole machinery 
of life. Man selects only for his own good—Nature only for 
that of the being which she tends. * * * * Under nature, 
the slightest differences of structure or constitution may well 
turn the nicely-balanced scale in the struggle for life, and so be 
preserved.” 
The more closely an animal resembles its surroundings in form 
and colour so much the more easily can it elude its pursuer, and 
also escape detection when approaching its own prey. Take for 
example those moths whose wings are coloured aud veined like the 
fallen leaves on which they lie motionless, or the hunting spiders 
which mimic flower buds, or the large caterpillars which resemble 
poisonous snakes. Or the sand-coloured insects of the desert 
which according to Grant Allen ‘‘have become sand-coloured 
because the least sandy were perpetually picked out for destruction 
by their ever watchful foes, while the most sandy escaped and 
multiplied. In the desert, a black, white, or red insect would be 
immediately detected and devoured by its natural enemies the birds 
and lizards. But any yellowish insects would be less likely to attract 
attention at first sight, and would be overlooked as long as there 
were any more conspicuous individuals. So that m a short time 
the desert would be depopulated of all but the yellowest insects, 
which would survive and become the parents of future generations.”’ 
In conformity with this law which is in reality a ‘‘ ceaseless 
struggle for food and for life,” we find that most animals are pro- 
tectively coloured, except those which are so constituted as to need 
no such protection. This law of mimicry has been investigated by 
many of nature’s lovers since first its existence was .demonstrated 
by Darwin. Within the last few months most interesting observations 
in connection with it have been published by Professor Drummond 
in his fascinating work on ‘‘ Tropical Africa.”’ I cannot do better 
than give you one or two of his most striking illustrations in the 
brief space of time that is allotted me this evening. 
Professor Drummond’s opinion is that mimicry serves not only 
as a natural method of protection, but also as warning. For 
instance, many of the most brilliantly coloured tropical butterflies 
are inedible owing to the presence in their bodies of acrid juices. 
Their gorgeous hues are thus hung out as danger signals to their 
natural enemies, the birds, monkeys, and lizards, which having’ 
once feasted upon similar insects have no wish to repeat the ex- 
periment. ‘The same rule,” he adds, ‘applies to all bees, 
