Natural Selection and Adaptation 275 
older naturalists who thought and spoke with Burchell of “the intention 
of Nature” and the adaptation of beings “to each other, and to the 
situations in which they are found,’ could have conceived the 
possibility of evolution, they must have been Jed, as Darwin was, by 
the same considerations to Natural Selection. This was impossible 
for them, because the philosophy which they followed contemplated 
the phenomena of adaptation as part of a static immutable system. 
Darwin, convinced that the system is dynamic and mutable, was 
prevented by these very phenomena from accepting anything short of 
the crowning interpretation offered by Natural Selection’, And the 
birth of Darwin’s unalterable conviction that adaptation is of 
dominant importance in the organic world,—a conviction confirmed 
and ever again confirmed by his experience as a naturalist—may 
probably be traced to the influence of the great theologian. Thus 
Darwin, speaking of his Undergraduate days, tells us in his Auto- 
hiography that the logic of Paley’s Evidences of Christianity and 
Moral Philosophy gave him as much delight as did Euclid. 
“The careful study of these works, without attempting to learn 
any part by rote, was the only part of the academical course which, 
as I then felt and as I still believe, was of the least use to me in the 
education of my mind. I did not at that time trouble myself about 
Paley’s premises; and taking these on trust, I was charmed and 
convinced by the long line of argumentation®.” 
When Darwin came to write the Origin he quoted in relation to 
Natural Selection one of Paley’s conclusions. “No organ will be 
formed, as Paley has remarked, for the purpose of causing pain or for 
doing an injury to its possessor®.” 
The study of adaptation always had for Darwin, as it has for 
many, a peculiar charm. His words, written Nov. 28, 1880, to 
Sir W. Thiselton-Dyer, are by no means inapplicable to-day : “Many 
of the Germans are very contemptuous about making out use of 
organs ; but they may sneer the souls out of their bodies, and I for 
one shall think it the most interesting part of natural history 4.” 
Protective and Aggressive Resemblance: Procryptic and 
Anticryptic colouring. 
Colouring for the purpose of concealment is sometimes included 
under the head Mimicry, a classification adopted by H. W. Bates in 
1 “T had always been much struck by such adaptations [e.g. woodpecker and tree-frog 
for climbing, seeds for dispersal], and until these could be explained it seemed to me 
almost useless to endeavour to prove by indirect evidence that species have been modified.” 
Autobiography in Life and Letters of Charles Darwin, Vol. 1. p. 82. The same thought is 
fepeated again and again in Darwin’s letters to his friends. It is forcibly urged in the 
Introduction to the Origin (1859), p. 3. 
® Life and Letters, 1. p. 47. 3 Origin of Species (1st edit.) 1859, p. 201. 
‘ More Letters, u. p. 428. 
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