544 MRS. R. HAIG THOMAS OX 



conversely fi'om the female to the male, or a pattern niny be 

 transferred from one area in the parent species to another area 

 in the F. 2 offspring. I have noticed that these pattei'n-tians- 

 ferences are inclined to remain fixed and constant. 



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

 occurred seemed to inhibit the appearance of pattern. 



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

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

 colour, both coloui-s were found on the breast of F. 2 Th. ohscura, 

 the rec[ of 2)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 offspring 



much of the male pkimage of her species. 



(3) In the F. 2 generation, the offspring of F. 1 female x 



Versicolor male, the Veisicolor 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 offspiing, whilst he has not transmitted every 

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

 offspring; repeating exactly the results of the original 

 experiment with gennceus. 



Are we, then, to suppose that son:ie of the gametes of this 

 Versicolor male contained all the factors representing the tem- 

 perament and habit, the colouj', pattern, and dimension of plumage, 

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

 even the factor for size of egg, 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 difficult to conceive. 



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

 opposed to expectation. 



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

 togenesis in the Gall-fly, also his researches on sex-limitations 

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

 would consider the above facts in relation to his tlieory of sex : 

 Male gametes S O female gametes S $ 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. 



