470 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



of different strains, but claims that by his method (see above, p. 462) 

 this can be increased to 70 or 80 per cent. 



So far as my experience goes, the actual output of doubles 

 yielded by the different ever-sporting strains is the same for all ; as 

 stated above, it remains constant, and may be put at about 53 or 57 

 per cent. It will suffice to state here that this estimate is based on 

 numerous observations carried on through a number of years. A full 

 account of the experiments and a discussion of the theoretical conclu- 

 sions to be deduced therefrom regarding the gametic constitution of 

 these forms will be found elsewhere.* But if this proportion represents 

 the maximum output which we are unable artificially to increase, it 

 remains to consider if there is any method by which we can circumvent 

 Nature's limit, and so achieve a better result in our flower-beds. 



Certain observations made in the course of the last year or two 

 have convinced me that in some cases at all events this can be done. 

 I had noticed that the proportion of doubles to be seen in the flower- 

 beds of a College garden in Cambridge appeared to be far in excess 

 of expectation. Careful counts fully confirmed this observation. The 

 doubles were undoubtedly enormously in excess of the singles. Either 

 the strain in question — a magnificent intermediate hoary white — 

 must be quite exceptional in the matter of output of doubles and in 

 this respect differ from all strains previously investigated, or the 

 excess must be due to some process of selection. The counts made 

 in four successive years gave the proportion of doubles shown below — 

 a proportion which in each case far surpasses the 53 or 57 per cent, of 

 expectation. 



Date. Number of Number of Doubles. 



Singles. 



1911 28 194 or about 85 per cent. 



1912 - 17 93 » 84i 



1913 30 180 „ 85J 



1914 55 216 „ 80 



These results were clearly not the outcome of a higher death-rate 

 among the singles after planting out, for in none of these years were 

 the gaps in the ranks of the flowering plants at all numerous, and in 

 two seasons every individual planted out was recorded. Nor, certainly, 

 was it to be attributed to any method of conscious selection such as 

 that practised by Chate. The gardener who had raised the plants 

 was as unable as myself to account for his success. The method 

 pursued was the simple one of taking each year a sufficient number of 

 the most forward and well-grown plants to fill the beds and discarding 

 the rest. The strain was always kept going, the seeds harvested in 

 any year supplying the plants for the next season but one. But it 

 might be that a certain unconscious selection in favour of the doubles 

 had been made at some point. If the single plants should prove to be 

 slower growing to begin with and present a less robust appearance at 



* Saunders, Journal 0} Genetics, loc, cit. See also Comptes rendus, loc. C4f., 

 and Journal Roy. Hort. Soc, loc. cit. 



