116 ESCHSCHOLTZIA CALIFOKNICA. CHAP. IV. 



throe long rows, however, were not of quite equal lengths, and 

 the plants were much crowded, so that it would have been ex- 

 tremely difficult to have ascertained how many capsules were 

 produced by them, even if I had been willing to undertake so 

 laborious a task as to collect and count all the capsules. But 

 this was feasible with the plants grown in pots in the green- 

 house; and although these were much less fertile than those 

 growing out of doors, their relative fertility appeared, after care- 

 fully observing them, to be the same. The nineteen plants of 

 the English-crossed stock in the pots produced altogether 240 

 capsules; the intercrossed plants (calculated as nineteen) pro- 

 duced 137 '22 capsules; and the nineteen self-fertilised plants, 

 152 capsules. Now, knowing the number of seeds contained in 

 forty-five capsules of each lot, it is easy to calculate the relative 

 numbers of seeds produced by an equal number of the plants of 

 the three lots. 



Number of seeds produced by an equal number of naturally- 

 fertilised plants. 



Seeds. 

 Plants of English-crossed and self-fertilised 



parentage as 100 to 40 



Plants of the English-crossed and intercrossed 



parentage as 100 to 45 



Plants of the intercrossed and self-fertilised 

 parentage as 100 to 89 



The superiority in productiveness of the intercrossed plants 

 (that is, the product of a cross between the grandchildren of the 

 plants which grew in Brazil) over the self-fertilised, small as it is, 

 is wholly due to the larger average number of seeds contained in 

 the capsules ; for the intercrossed plants produced fewer cap- 

 sules in the greenhouse than did the self-fertilised plants. The 

 great superiority in productiveness of the English-crossed over 

 the self-fertilised plants is shown by the larger number of 

 capsules produced, the larger average number of contained seeds, 

 and the smaller number of empty capsules. As the English- 

 crossed and intercrossed plants were the offspring of crosses in 

 every previous generation (as must have been the case from the 

 flowers being sterile with their own pollen), we may conclude that 

 the great superiority in productiveness of the English-crossed 

 over the intercrossed plants is due to the two parents of the 

 former having been long subjected to different conditions. 



