( Ixix ) 



other. We were driven to believe therefore that Jiippocoon 

 was recessive and that the rarer forms were relatively to it, 

 heterozygotes or true dominants. But if the rarer females 

 were true dominants mated with males carrying the recessive 

 hippocoon, none of the offspring should have borne the appear- 

 ance of the latter. If, on the other hand, they were heterozy- 

 gotes with the appearance of the dominant, the matings should 

 have given the result obtained, viz. a mixture of two female 

 forms. The numerical expectation was half of the female 

 parent form to half of the recessive hippocoon, and approxi- 

 mately half and half were obtained in 3 out of 4 of Mr. Swynner- 

 ton's families from the rarer female parents, although the 

 numbers were unfortunately very small. The same interpre- 

 tation held for Mr. Lamborn's family of approximately half 

 dionysus and half hippocoon. If we suppose that the recessive 

 female parent, hippocoon, had mated with a male carrying 

 dionysus as a heterozygote, the result was in accordance with 

 Mendelian expectation. 



It had been shown that if hippocoon were dominant we 

 should not expect many of this form to be heterozygotes, 

 because of the fewness of matings with males carrying the 

 rarer forms. But the opposite was true of these latter; 

 for the vast predominance of the recessive would ensure that 

 nearly all their matings would be with recessives and would 

 produce heterozygotes. And these heterozygotes would 

 nearly always mate with recessives producing again a mixture 

 of heterozygotes and recessives. It might be safely assumed 

 that these relatively rare forms bearing the appearance of 

 a pattern dominant to the abundant hippocoon were nearly 

 always heterozygotes and not true dominants, and the results 

 obtained were in accordance with this assumption. 



Mr. G. H. Hardy, F.R.S., of Trinity College, Cambridge, 

 had written (Science, N. S., Vol. xxviii, No. 706, pp. 49-50, 

 July 10, 1908) on the stability of Mendelian populations and 

 had shown that whatever be the proportion between dominants, 

 heterozygotes and recessives, equilibrium was reached in the 

 second generation and would persist unless disturbed by selec- 

 tion or some other cause. His equations started from known 

 proportions whatever these may have been . Nowin P. dardanns, 



