25S X 0)1-1 salable Races. 



Here again there is no discernible correlation. I have 

 obtained the same result in other years. From this we 

 see that in this case at least selection must not be founded 

 on the different llowers of a plant but on the individual 

 plants. However, the possible influence of the various 

 grades of branching independently of the number of 

 petals remains to be investigated. 



But whereas no internal causes were found which 

 determined the pleiopetaly in the individual flowers, the 

 external causes could be discovered the more readily. 

 This character follows the general rule; for the higlier 

 the nutrition and the more favorable the environment 

 the more petals are produced per flower. The following 

 experiments and ol)servations will prove this. 



I shall first refer to an observation for which un- 

 fortunately I can give no numerical corroboration, but 

 which may throw some light on the independence of the 

 character of the flowers, of the order of branching. In 

 the summer of 1892 when I examined all the flowers of 

 my culture, and recorded the number of their petals twice 

 a week, I was struck by the fact that the high numbers 

 fell on particular days whilst on other days only low or 

 intermediate numbers were observed. This would seem 

 to indicate that during the development of the flowers 

 in May and June pleiopetaly is influenced by weather 

 conditions, in such a way that flowers which are in the 

 susceptible period of their development during fine 

 weather wn'll produce more petals, quite independently 

 of the order of the branch which bears them. 



This conclusion is supported by another set of obser- 

 vations. In September 1892 the flowers, on the wliole, 

 produced more petals than they did in August of tlie 

 same vear. Or. to be more accurate, the number was sfreater 



