138 Doubles in Stocks 



Though Chate mentions that his conclusions are the result of 

 observation, the cultivation of Stocks having been carried on in his 

 family for more than fifty years, he adds, in the one case in which he 

 gives the number of seeds sown, that his percentage is calculated on 

 a sample of only 100 seeds; hence it may be that in other cases also 

 his sowings may not have been on a large enough scale to give reliable 

 ratios. On the other hand one is disposed to think that some further 

 foundation must have appeared to exist both for these statements and 

 for those made from time to time by present day florists. 



I have elsewhere shown that a differentiating character which has 

 the appearance of leading to an increased output of doubles is the 

 seemingly slightly greater viability of the double-producing seeds as 

 compared with the single'. But this factor will not, we may suppose, 

 affect the present enquiry, since the percentages claimed would certainly 

 be quoted from sowings oi fresh, seed, not of seed which lias been kept 

 for several seasons. How then are we to explain such high records 

 as those quoted by growers, assuming them to be based on accurate 

 counts ? In the course of these experiments I had come to the view 

 that a rather greater vigour or rapidity of growth characterised the 

 doubles as compared with the singles. If this difference could be 

 established beyond doubt it might account for the exceptional records 

 mentioned above. An opportunity recently presented itself to test this 

 supposition on a fairly large scale, and a preliminary statement of the 

 results was given at the Meeting of the British Association in 1914, 

 when I expressed my belief that herein lies the explanation of these 

 abnormally high percentages^. I am now able to give in full the 

 evidence upon which this conclusion is based which falls under two 

 heads : 



1. A comparison of results obtained in the flower-bed with those 

 of a control experiment carried out on the same material, showing that 

 the apparent excess output of doubles in the first case was fictitious. 



2. A comparison of the number of singles and doubles recorded 

 among the more and the less vigorous individuals respectively, showing 

 that a proportion in excess of expectation is furnished by the more 

 vigorous individuals, which is counterbalanced by a corresponding deficit 

 among the less vigorous plants. 



1. During the last four years I have been able to record the results 

 obtained with a certain fine strain of Litermediate, hoary, white Stocks 



' Journal of Genetics, loc. cit. p. 3ti2. 



2 See Jourmd Royal Uort. Soc. 19irj, Vol. xr,. Part iii. p. 471. 



