342 Donbleness in Stocks 



mating, but several sister plants gave a deficiency of doubles iu several 

 F. families when used either as seed or pollen parent in matings with 

 various sulphur-whites — the only other d-ioim besides light purple with 

 which flesh was crossed. Thus from one sister plant, used as the pollen 

 parent to fertilise a particular sulphur-white, five F„ families were 

 obtained, composed as follows : 



Totals 153 24 



Now this particular sulphur-white was used in many matings. It 

 gave a distinct excess of doubles, as we should expect, both when self- 

 fertilised (viz. 5 s., 11 d.) and when crossed with pollen fiom five other 

 eversporting forms, the seven F^ families thus produced, comprising alto- 

 gether -57 s., 9.5 d. 29 F^ families raised from these latter matings gave 

 a total of 418 s. and 597 d. We have therefore every reason to suppose 

 that this particular sulphur- white was producing as large a proportion 

 of ovules carrying donbleness as the typical eversporting plant. It 

 therefore looks as though the deficiency observed in F.j from the mating 

 between flesh and this particular sulphur-white could not be attributed 

 wholly to the sulphur-white. But if the flesh parent is partly or wholly 

 responsible for the deficiency in this case, then we shall probably be 

 right in regarding the flesh parent as similarly responsible in other 

 matings where sister plants were employed. 



2. On the other hand the c^-glabrous light purple individual used 

 as the pollen parent in the union with no-c?-flesh was also similarly 

 employed in matings with two rio-c^-cream individuals. In both these 

 matings there was a distinct deficiency of doubles in Fo. Nine F^ cross-, 

 breds in the one case gave 186 s. and 20 d., 5 F^ cross-breds in the other 

 gave 75 s. and 9 d. Now one of these same cream plants was also 

 similarly used as the $ parent iu a mating with f?-glabrous azure, and 

 here none of the F^ families showed a deficiency, hence the cause of the 

 deficiency in the mating between cream and light purple cannot be 

 ascribed altogether to the cream, but must be due, wholly or in part, to 

 the light purple individual which was used as the pollen parent in the 

 mating with flesh as well as with cream. 



