74 MIMULUS LUTEUS. CHIP. Ill 



as 100 to 92. We thus see how immensely superior in height 

 the Chelsea-crossed are to the intercrossed and to the self- 

 fertilised plants. They began to show their superiority when 

 only one inch high. They were also, when fully grown, much 

 more branched with larger leaves and somewhat larger flowers 

 than the plants of the other two lots, so that if they had been 

 weighed, the ratio would certainly have been much higher than 

 that of 100 to 56 and 52. 



The intercrossed plants are here to the self-fertilised in 

 height as 100 to 92; whereas in the analogous experiment 

 given in Table XIX. the intercrossed plants from the self- 

 fertilised plants of the sixth generation were inferior in height 

 to the self-fertilised plants in the ratio of 100 to 110. I 

 doubt whether this discordance in the results of the two 

 experiments can be explained by the self-fertilised plants in the 

 present case having been raised from spontaneously Self- 

 fertilised seeds, whereas in the former case they were raised 

 from artificially self-fertilised seeds; nor by the present plants 

 having been self-fertilised during two additional generations, 

 though this is a more probable explanation. 



With respect to fertility, the twenty-eight Chelsea-crossed 

 plants produced 272 capsules; the twenty-seven intercrossed 

 plants produced 24 ; and the seventeen self-fertilised plants 17 

 capsules. All the plants were left uncovered so as to be naturally 

 fertilised, and empty capsules were rejected. 



Capsules. 



Therefore 20 Chelsea-crossed plants would have produced 194-29 

 20 Intercrossed plants 17 '77 



20 Self-fertilised plants 20 'OC 



Grains, 

 The seeds contained in 8 capsules from the Chelsea- ) j.^ 



crossed plants weighed | 



The seeds contained in 8 capsules from the Intercrossed ) Q.gj 



plants weighed ...,..} 



The seeds contained in 8 capsules from the Self-fertilised j. 0-33 



plants weighed ...... 5 



If we combine the number of capsules produced together with 

 the average weight of contained seeds, we get the following 

 extraordinary ratios : 



Weight of seed produced by the same number ) inn t 4 

 of Chelsea-crossed and intercrossed plants . J 1UU TO 



