PSYCHOLOGY AND SCIENTIFIC METHODS 301 



derfully mimicked by the forms anthedon and dubia of the allied 

 species. I very much hope that Mr. Lamborn will be able to breed E. 

 dinarcha, and ascertain whether the Mendelian relationship exists 

 between its two forms. 7 But whether this is so or not, there can be 

 little doubt that these forms exhibit to us an initial stage in an evo- 

 lutionary journey which has been carried very much further by 

 anthedon and dubia. 



There are other interesting facts which remain to be further in- 

 vestigated in the Mendelian relationship of these mimics. Mr. Lam- 

 born informs me that the recessive form anthedon shows a well- 

 marked tendency to appear seasonally; so that, during part of the 

 year, he finds only this form on the wing. Then, later on, dubia 

 suddenly appears. Such a phenomenon is extremely difficult to ex- 

 plain on ordinary Mendelian lines. Either we are faced by some 

 undiscovered aspect of Mendel 's law or the dominant form must have 

 the power of lying dormant in some one or more of its stages, and 

 then suddenly appearing. Against this latter hypothesis is the fact 

 that in the seven large families bred by Mr. Lamborn, and now in the 

 Oxford University Museum, there was not the slightest evidence of 

 any difference between the two forms in this respect. 



Edward B. Poulton. 

 Oxford University Museum. 



1 Returning to Oxford at the end of the Easter vacation, I find a letter from 

 Mr. Lamborn written March 29, 1912, from Oni Camp, near Lagos, telling me 

 that he has now succeeded in obtaining eggs from both forms of E. dinarcha, and 

 that the larva? are doing well. We may hope for evidence, which will decide 

 whether these two forms are a Mendelian pair, in a few weeks. I am very 

 fortunate in having friends in the tropics who are so often able to supply us 

 with just the very solutions for which we are looking with the utmost interest 

 and eagerness. — E. B. P. 



