THE DOUBLE STOCK, ITS HISTORY AND BEHAVIOUR. 459 



flowers." He further adds that " the double only is admitted into 

 the gardens of the Curious, the single remaining in some nursery to 

 bear seed." * It is clear, however, that this essential underlying fact 

 that among Stocks there exist two distinct hereditary types of single, 

 viz. those which produce doubles and those which do not, was not 

 generally appreciated until considerably later, and it was ignorance 

 of this fundamental point which delayed the full understanding of 

 such observations as were from time to time recorded, and led to the 

 acceptance of various theories which claimed to account for the 

 appearance of doubles, but which, when tested, proved to have no 

 foundation in fact. As some of these are still current at the present 

 day, it may be worth while to refer briefly to them here. That each 

 of these several hypotheses fails to account for the facts becomes 

 apparent as soon as it is tested by observation and experiment. 



Various methods which have been advocated in the past as leading to 

 the production of doubles among Stocks, but which have proved on investiga- 

 tion to be without effect : — 



1. The sowing of seeds or the transplantation of young plants at 

 particular phases of the moon. At the present day comment on this 

 method is superfluous. 



2. Special treatment (probably of the nature of manuring) and 

 frequent transplantation of young plants. This, as we have seen, was 

 the view held by the earliest writers on the subject. A later form 

 of the same idea, current after it was realized that the doubles were 

 obtained from seed, was that of sowing the seed in a different soil 

 from that in which the parent plants had been grown (Bradley, 1728). f 



3. The selection as seed-bearers of singles on which were found 

 flowers having one or two extra petals (Hill, 1757). 



4. The planting of doubles among or in close proximity to singles, 

 in order that the single plants might, as supposed, be fertilized by 

 pollen from the doubles. This was one of the earliest and most wide- 

 spread of beUefs held by the gardener. His confidence in the method 

 is illustrated by the following passage from the Herbal of Thomas 

 Green (1820), the matter contained in which is stated on the title- 

 page to be " collected from indisputable authorities." We find under 

 the head Cheiranthus incanus (Stock-Gilliflower) the following : — 



" A very sure way of obtaining many double flowers, is to make 

 choice of those single flowers which grow near many double ones, for 

 those seeds saved from plants growing in beds close to each other, if 

 there happened to be a good many double flowers among them, have 

 been always found to produce a much greater number of plants with 

 double flowers, than those which have been saved from plants of 

 the same kinds which grow single in the borders of the flower- 

 garden." X 



* pp. 162. 163. 



t References to the works of the writers here mentioned are not repeated 

 where they have been given in the preceding pages. The authors' names are 

 quoted here merely to show the dates at which the different views were current. 



X The Universal Herbal. 



212 



