754 THE AMERICAN NATURALIST [Vol. XLIV 



univoltinism and bivoltinism 7 are not inconsistent with Men- 

 delian theory. The difficulty in interpretation is due to the 

 fact that the characters in question are exhibited by one sex 

 only. The same difficulty arises in following out the cross be- 

 tween white and red corn, since red shows only as an internal 

 character. 



Hagedoorn, 8 in mating an albino mouse having the barring 

 (agouti) character with a homozygous yellow female, finds the 

 barring and the yellow color to be allelomorphic to each other. 

 Certain yellow individuals mated to black gave only yellow 

 offspring. It is probable that the yellow contains an inhibiting 

 factor for black. Other yellow mice of a different shade mated 

 to black gave black young. His results confirm those of Goodale 

 in that he finds the bankiva pattern and color in Bantams 

 crossed with Brown Reds to behave as if the bankiva pattern 

 were allelomorphic to femaleness. When females of the bankiva 

 type were used in the cross the male offspring were all bankiva 

 and the females all Brown Red. When the cross was made in 

 the opposite direction both sexes were of bankiva type. He 

 also found (page 26) some bankiva females apparently homozy- 

 gous for bankiva pattern. His data are not full or complete 

 on this point. 



On page 29 he reports that the cross between Primula sinensis 

 and P. stellata gives /'. pijranndaUs. F, from this cross gives 

 25 per cent, sinensis, 25 per cent, sldlala, and 50 per cent. Pyr- 

 aniidaHs, although the two parent forms differ in more than one 

 respect, the differences apparently being coupled. 



The writer has frequently suggested that if a careful search 

 were made for more cases of what Bateson has termed "false 

 allelomorphs" they might be found to be more abundant than 

 they are thought to be. Those cases which have been dis- 

 covered show that such phenomena are not discovered usually 

 unless one is looking for them. We have now a considerable 

 number of cases of sexual dimorphism in which some somatic 

 character acts as an allelomorph to femaleness. Presumably, 

 these sex-limited characters would act as allelomorphs to each 

 other if brought together in the same zygote. We have already 

 referred to the barring of Plymouth Rocks and to the Jungle 

 'Jour, of Exp. Zool., Vol. 7, No. 4. 



•Hagedoorn, A. L., < < Meridian I nln ritanee, " Arch. f. Entw. d. Orqan.. 

 Vol. 28. H. 1. 



