DARWINISM DEFENDED. 175 



mimicry can be brought about as the famous case of Kal- 

 lima, the butterfly that simulates in colour, shape, and inti- 

 mate details of pattern such as veins, flecks, 

 The case of fungus spots, etc., a dead leaf with such fidelity 

 as to make it the wonder of every one who sees 

 it and the classic example of the possibilities of such protect- 

 ive resemblance. And he shows well that whatever diffi- 

 culties selection may have in its necessary dependence on 

 the chance occurrence of the proper numerous and neces- 

 sarily simultaneously appearing variations to explain the 

 gradual development of such a specialisation, the only other 

 explanations so far offered are even more ludicrously de- 

 pendent on "luck." Piepers, 9 the most active and polem- 

 ically vigorous of all special opponents of the Darwinian 

 explanation of protective resemblance and mimicry, says : 

 ''Chance alone can bring about such a correlation." As 

 Plate well says, "It is not without its comic aspect that a 

 violent antagonist of the selection theory should be found 

 clinging to the same safety-anchor 'chance/ that usually 

 is the constant reproach of the Darwinian. ... It would not 

 be difficult," continues Plate, "to refer to still other examples 

 to show that a needed selective value can often be attained 

 at the same time by the individuals of a species through 

 various means, by which the probability that this type of 

 adaptations can arise is correspondingly increased. But 

 one point should never be forgotten and that is it is always 

 first the variability, and second the selection. If no varia- 

 tions appear there can be no progress, and if the struggle 

 for existence were too severe the [non-varying] species 

 would die out. Strictly speaking, the question, how is it 

 possible that the right variations can be relied on to ap- 

 pear at the right time? is really inverted and therefore 

 incapable of receiving a correct answer. One can only- 

 say : If a complex adaptation has arisen through selec- 

 tion, then it is certain that the necessary modifications 



