THE COLORATION PROBLEM. 157 



probably explain the rising of a balloon as due to a cessation of the 

 operation of gravity. This mistake does not detract from the sound- 

 ness of the theory of gravitation. Likewise, there may be specific 

 instances in which a superficial observer might assume a synapose- 

 matic combination where such did not exist ; but I cannot for the 

 life of me see that that throws any doubt on the correctness of the 

 theories. An individual might readily be led to suppose that a group 

 of Boarmias were a synaposematic combination instead of all being a 

 syncryptic assemblage. Mr. Wheeler suggests that the theories might 

 be applied where almost demonstrably applicable, but rejected in other 

 cases. The theories would lose their value to me entirely if they 

 could not be applied throughout and to their logical extremity. I do 

 not believe that natural laws operate in a piece-meal style, every- 

 thing that I know tends to make me believe that every law 

 in nature is carried into operation in its entirety and to its 

 logical extremity, and that the supposed exceptions are the result 

 of inter-actions of laws which we have failed to elucidate. Prof. 

 Poulton remarks to me in litt., "There are such accidental resemblances 

 between patterns of butterflies in different regions, but they are very 

 rare, if on the theory of chances we assumed that an equal proportion 

 of the mimics within the same region are also due to accident, it would 

 cut off a small fraction of our examples, and in very many cases we 

 have changes in mimicry in relation to geographical distribution over 

 the region, and such are of course beyond any doubt." 1 do not, of 

 course, mean to say that it is not possible to fancy a cryptic resem- 

 blance existing between two objects from remote parts of the globe, 

 since one lump of dirt is very like another. It may be well that 

 cryptic resemblance to the sand cliffs of Cape Colony would be quite a 

 serviceable resemblance of a sand cliff" in Britain. Moreover, I can- 

 not follow Mr. Wheeler in his suggestion that the theories may apply • 

 to one Order, and need not necessarily apply to another. Like results 

 are the result of like causes in probably every Order. The physical 

 means and machinery producing the results may vary infinitely, but 

 the primal cause of the tendency and the goal aimed at are alike. For 

 example, assuming the cause of mimicry to be the stressof the struggle 

 for lire, and the result attained be a mimetic resemblance, the means 

 used are very various, it may be by increase or reduction of scales, 

 increase or decrease of pigment, but the end attained by these 

 various modifications is a passing likeness, and the operative causes 

 shew the theories at work practically. Lieut. -Col. Manders' Scotch 

 attitude, however canny, will not enable him to occupy a place of 

 neutrality, since there being no other rational explanation of the 

 observed phenomena in the field, if he does not accept the explanation 

 he must be treated as an opponent, and I think the opponents of the 

 theories should state clearly, what I cannot see that they have done as 

 yet, whether they say the Batesian and Miillerian theories are bad as a 

 whole or only bad as applied to lepidopterous imagines. 



If the former, it is open to them to supply, and in fact necessary 

 that they should supply, a rational explanation of the extraordinary 

 likenesses between organism and organism, and organism and inorganic 

 surroundings. I am fully aware that generally it is a bad method of 

 arguing (and it is a method I have no love for) that you must accept 

 my explanation, however futile, unless you can put one less futile in 



