43* 



THE AMERICAN NATURALIST [VouXLTV 



Case 3. — The statements of Russo concerning this case are very 

 incomplete. A spotted "Olandese" female after lecithin treat- 

 ment was mated with a silver-gray male and produced three 

 spotted and one self-colored young, which are figured. Before 

 treatment with lecithin she had been mated under normal con- 

 ditions {once with the same silver-gray male, "mit demselben 

 grau Mannchen einmal," but we are not told that he was the 

 father of the young, we are rather left to infer that she may 

 have mated with other males also. Five young were afterward 

 born — "es erzeuute dann spater 5 Junge." all gray. Again the 

 female was mated under similar uncertain conditions, "unter 

 den gleichen Bedingungen," and produced four gray young. 

 Since in a third litter, after lecithin treatment, she produced 

 spotted young, it is concluded by Russo that the lecithin treat- 

 ment was responsible for the changed result. But before ac- 

 cepting this conclusion we should like to ho assured that one and 

 the same male was used in both cases. The silver male may have 

 been heterozygous in spotting, the father of the earlier litters not. 



Case 4.— Two Himalayan (albino) females, sisters, were mated 

 with the same black male. One of the two was lecithin treated, 

 the other was not. Both produced black young, five each. This 

 looks like a bad case to select in support of lecithin influence, but 

 we are told further that in the following year, when lecithin 

 injections were employed forty days previous to copulation, a 

 litter of two Himalayan young was obtained. The sire of the 

 litter is figured but we are not told whether he was the same 

 as the one used the previous season. This omission is signifi- 

 cant. The male figured was evidently heterozygous in albi- 

 nism, but it is a pretty safe guess that he was not identical 

 with the male used the previous season, which was in all 

 probability homozygous in black. In this case as in the others 

 described by Russo it is impossible to avoid the impression 

 that the author is not making a full and frank statement of 

 facts but is stating half-truths likely to mislead the unwary. 

 In Jordan's case this is exactly what has happened. He says: 

 "The evidence here appears unequivocal that external conditions 

 (e. ej., nutrition) can determine the kind of sex and entirely 

 vitiate the. M< ndelian schi me of ordinary crosses" \ italics mine!. 

 I have, however, presented in detail all fix ev'uh nee which Russo 

 gives in support of the assumed vitiation of Mendel ian inherit- 

 ance. I think the reader will agree with me that the evidence 



