364 Doubleness in StocJcs 



In 1908, 30 more seeds of this plant were sown ; only 2 germinated ; 

 both were double. 



In 1909, 47 more seeds were sown ; only 7 germinated and again all 

 were double. 



Of 5 seeds, harvested also in 1906, from a sister plant, but not sown 

 till 1909, only 2 germinated and both produced doubles. 



In 1908 nearly 200 seeds harvested from 5 of the F^ singles were 

 sown ; 40 germinated of which 27 lived to flower, 5 being single and 

 22 double. The families were composed as follows : 



Family 1. >30 seeds sown. 1 germinated and produced a double 



,, 2. 34 ,, ,, 12 „ 8 were double, 4 died before 



flowering 

 „ 3. 33 „ ,, 15 „ 8 were double, 4 died before 



flowering and 3 were single 

 ,, 4. 30 „ ,, 12 „ 5 were double, 5 died before 



floweriug and 2 were single 



All the seeds from the fifth F^ plant failed to germinate. 



In 1910, 85 more seeds from 3 of these same F^ plants were sown, 

 but none germinated. 



About 500 seeds from 20 others among the F^ singles gave a total 

 of 79 singles and 114 doubles. Here the proportion of seeds still 

 capable of germination, though less than 50 per cent., was considerably 

 greater than in the lot sown in 1908, and the result is not very different 

 from what we should expect had the seeds been sown in the season 

 following that in which they were harvested. From this and other 

 facts it is evident that the length of time during which the seeds retain 

 their power of germinating is not fi.xed but depends probably on the 

 quality of the seed in the first instance, and on the conditions under 

 which it is kept. 



iii. In 1908, 69 seeds of a sulphur-white which had been harvested 

 in 1906 gave 23 singles and 32 doubles. 



In 1910, 128 more seeds were sown; only 5 germinated of which 

 4 lived to flower : all were double. 



A similar increase in the proportion of doubles was observed in 

 many cases where the seed was originally of bad quality, and where 

 only a small percentage germinated even when sown the following 

 season. This is well shown in the case of the two type forms from 

 which the largest sowings were made in 1910. Owing to a bad season 

 in 1909 a great deal of the seed harvested was of miserable quality 

 and a large proportion failed to germinate. Though no real line of 



