in Hybridisation 341 



of the seeds. All seeds should therefore appear round and 

 yellow, if the theory be justified. In the second and fourth 

 experiments, on the other hand, one union is hybrid in 

 form and in colour, and consequently the seeds are round 

 and yellow ; another is hybrid in form, but constant in the 

 recessive character of colour, whence the seeds are round 

 and green ; the third is constant in the recessive character 

 of form but hybrid in colour, consequently the seeds are 

 wrinkled and yellow ; the fourth is constant in both recessive 

 characters, so that the seeds are wrinkled and green. In 

 both these experiments there were consequently four sorts 

 of seed to be expected viz. round and yellow, round and 

 green, wrinkled and yellow, wrinkled and green. 



The crop fulfilled these expectations perfectly. There 

 were obtained in the 



ist Experiment, 98 exclusively round yellow seeds ; 

 3 r d 94 



In the 2nd Experiment, 31 round and yellow, 26 round 

 and green, 27 wrinkled and yellow, 26 wrinkled and green 

 seeds. 



In the 4th Experiment, 24 round and yellow, 25 round 

 and green, 22 wrinkled and yellow, 27 wrinkled and green 

 seeds. 



There could scarcely be now any doubt of the success 

 of the experiment ; the next generation must afford the 

 final proof. From the seed sown there resulted for the 

 first experiment 90 plants, and for the third 87 plants 

 which fruited : these yielded for the 



ist Exp. 3rd Exp. 



20 25 round yellow seeds ..... AB 



23 19 round yellow and green seeds . . . ABb 



25 22 round and wrinkled yellow seeds . . AaB 



22 21 round and wrinkled green and yellow seeds AaBb 



In the second and fourth experiments the round and 

 yellow seeds yielded plants with round and wrinkled yellow 

 and green seeds, AaBb. 



From the round green seeds plants resulted with round 

 and wrinkled green seeds, Aab. 



The wrinkled yellow seeds gave plants with wrinkled 

 yellow and green seeds, aBb. 



