THE THEORY OF MIMICRY 101 



others, Avhich is decidedly damagiug, especially on that 

 all-important point of discrimination. Prof. Punnet t's 

 comments on this and other evidence (page 113 '* Mimicry 

 in Butterflies") are very fairly put. The results from 

 the examination of the contents of birds' stomachs can 

 hardly afl'ord much satisfaction to the upholders of the 

 mimicry theory, and the data afforded by the results of 

 the examination of 40,000 birds by the Department of 

 Agriculture of the United States is most disastrous. 

 Only four contained remains of Lepidoptera. 



There is much in Professor Punuett's book with which 

 I am in accord, but the discussions that have ensued on 

 its publication have naturally afforded many opportuni- 

 ties for criticism, which have been taken the fullest ad- 

 vantage of by the other side, as might be expected when 

 such Xestors in Biological science as Prof, Poulton and 

 T)r. Dixey take the field. 



The " mutation '• theory, so far as I at present under- 

 stand it, does not appeal to me as an efficient substitute 

 for the simpler theory of mimicry by natural selection. 

 It changes the method, but leaves the causation or incen 

 tives obscure. 



Prof. Poulton, I think, has the best of the argument in 

 favour of small variations leading up to the perfected 

 image. The examples given in '^ The Hereditary Trans- 

 mission of Small Variations and the Origin of ButterMy 

 Mimicry '^ give many and good examples of the gradual 

 evolution of the markings and patterns on the wings of 

 Lepidoptera. 



Many illustrations are also afforded by Prof. Poulton 

 and others to demonstrate that small variations are 

 transmissable from female parent to their offspring, but 

 is this always so? Is it not dependent on the male being 

 homozygous to the female to use the Mendelian expres- 

 sion. The character selected in one illustration, that of 

 Dr. G. D. Hales Carpenter's paper, (Trans. Ent. Soc, 

 Lond., 1013) on '"the inheritance of small variations in 

 the pattern of P. dardanus/^ is the shape and size of the 



