A SUGGESTED EXPLANATION OF THE ABNOR- 

 MALLY HIGH RECORDS OF DOUBLES QUOTED 

 BY GROWERS OF STOCKS {MATTHIOLA). 



Br EDITH R. SAUNDERS, 



Lecturer, late Fellotv, Newnham College, Cambridge. 



During the last few years I have published a considerable amount 

 of evidence to show that the actual output of doubles among the strains 

 of Stocks now in cultivation does not on the average exceed 56 — 57 per 

 cent., and should perhajjs be put somewhat lower — possibly 53 — 54 

 per cent. These figures are based on the results of large sowings 

 carried out, during many seasons'. In these cultures care was taken 

 to obtain the fullest possible record from the sample sown ; no young 

 plants were discarded at any stage of the work, thus eliminating as far 

 as possible any effect of selection, conscious or unconscious. We still 

 however find percentages considerably higher than the above quoted 

 occasionally in current florists' lists, these percentages being based 

 presumably not merely on tradition but upon observation, since the 

 statements usually refer to newly introduced strains. In a recent 

 catalogue of an Erfurt firm of gi-owers, for example, 80 — 82 per cent, 

 of doubles is quoted for a new strain. In his treatise on the cultivation 

 of Stocks the French grower Chate li.sts some twelve double-throwing 

 strains ten of which will, he states, if treated according to his method, 

 yield as many as 70 or even 80 per cent, of doubles, although these 

 same strains ordinarily give only about 50 per cent, of doubles^. 



' See Reports to the Evolution Committee of the Royal Society, ii. 1905, p. 29 ; 

 m. 11106, p. 44; IV. 1908, pp. 4, 36. Journal of Genetics, 1911, Vol. i. No. 4, p. 303; 

 Journal Royal Hort. Soc. 1913, Vol. xxxviii. Part iii. p. 469. 



- Culture pratique des Giroflees, Paris, N. D. Chate's method was to remove all the 

 weaker branches, and to disregard the seed in the upper halt of the siliqua. Such 

 evidence as I have obtained on this point does not indicate any such localised distribution 

 of the double-producing seed as Chat^ suggests. 



