544 MRS. R. HAIG THOMAS ON 



conversely from the female to the male, or a pattern may be 

 transferred from one area in the parent species to another area 

 in the F. 2 offspring. I have noticed that these pattern-trans- 

 ferences are inclined to remain fixed and constant. 



Colour-transference also takes place, and sometimes where it has 

 occvirred seemed to inhibit the appearance of pattern. 



One instance was noticed where the breasts of the males of the 

 two races crossed, Th. amhersti and Th. picta, differing widely in 

 colour, both colours were found on the breast of F. 2 Th. ohscura, 

 the red o1 j^icta overlying the metallic green of amhersti. 



These appear to be the results of the second experiment : — ■ 



(1) The male parent transmitted to his F. 1 female offspring 



much of the female plumage of his species and the 

 dimension of the Qgg. 



(2) The female parent transmitted to her F. 1 male ofi'spring 



much of the male plumage of her species. 



(3) In the F. 2 generation, the offspi'ing of F. 1 female x 



Versicolor male, the Versicolor male seems to have trans- 

 mitted every character — bill, leg-colour, plumage, habit, and 

 temperament — of the female of his species to his F. 2 

 female offspring, whilst he has not transmitted every 

 character of the male of his species to his F. 2 male 

 offspi'ing; repeating exactly the results of the original 

 expeiiment with geiinceus. 



Are we, then, to suppose that some of the gametes of this 

 Versicolor male contained all the factors lepresentiug the tem- 

 perament and liabit, the colou)-, pattern, and dimension of plumage, 

 leg, and bill, and the bulk of the female of his species and 

 even the factor for size of ^gg, with the one exception of the 

 factor for the sex to which these belonged ? 



To the practical experimentalist, to the non-mathematical 

 simple observer, the hypothesis is difficidt to conceive. 



These phenomena seem to be of the nature of a sex-limitation 

 opposed to expectation. 



I have read with much interest Mr. Doncaster's account of game- 

 togenesis iir the Gall-fly, also his researches on sex-liraitations 

 published in ' Genetics,' and am interested to know how he 

 w^ould consider the above facts in relation to his theory of sex : 

 Male gametes c? female gametes J 5 with selective fertilisation 

 between the male gamete O (a non-determinant of sex) and the 

 female gamete S . 



I hope the material collected in these two experiments may be 

 thought of sufficient importance for the higher students of 

 Genetics to give it some attention, when probably the apparently 

 complicated problem will receive a simple explanation. 



