366 Douhleness in Stocks 



obtained as in the case where the seeds were sorted according to shape 

 (see below). Sometimes a higher proportion of doubles would be 

 obtained from the lower half, sometimes from the upper, making it 

 evident that no constant difference exists in the two regions with 

 regard to the distribution of the two kinds of seed. It seems in fact 

 probable that the distribution observed by Chat^ was accidental, and 

 not the result of any general arrangement throughout the individual. 



{h) On the possibility of distinguishing the seeds giving rise to 

 singles and doubles respectively. 



In several papers by earlier writers, treating of Stocks, we find the 

 statement repeated that more doubles are obtained from the lumpy 

 irregular-shaped seeds than from the typical regular disc-shaped seeds. 

 No figures are quoted in support of this view, which is probably the 

 outcome of an association of ideas rather than of critical experiments, 

 which would need to be carried out on a considerable scale in order to 

 allow for any disturbing effect due to the frequent marked irregularity 

 of distribution which has already been noted. So far no indication 

 has been observed of any connection between the shape of the seed 

 and the character of the flower. The glabrous-red race being one in 

 which many lumpy or irregular seeds constantly occur, the seeds from 

 a certain number of pods belonging to this race were sorted according 

 to shape, the flat seeds being sown separately in one lot, the irregular- 

 shaped seeds in another. It was found that cases where more doubles 

 were obtained from the flat seeds were about as numerous as those 

 where the reverse was true, and that so evenly did the variations in 

 the one direction balance those in the opposite direction that the ratio 

 obtained from the totals in the two cases was almost identical. Thus 

 in 1 906 the seeds of 10 pods of the red race were sorted before sowing. 

 The results were : 



From the flat seeds a total of 65 singles and 93 doubles or 1 : 1'43 

 lumpy „ 19 „ 28 „ 1 : 1-47 



Similar sowings in other years gave similar results. 



It seems much more probable that the irregular shape of the seeds 

 is connected with the way in which they are packed in the pod. In the 

 case of the cream race Princess May, and of a certain strain of sulphur- 

 whites, the pods are often some inches in length. The seeds are borne 

 at some distance from one another, and although a pod may contain 

 from 60 to 70 or even more, they do not overlap. They are so regular 



