in Hybridisation 71 



Although in these two experiments likewise some seeds 

 did not germinate, the figures arrived at already in the 

 previous year were not affected thereby, since each kind of 

 seed gave plants which, as regards their seed, were like each 

 other and different from the others. There resulted there- 

 fore from the 



2nd Exp. 4th Exp. 



31 24 plants of the form AaBb 



26 25 Aab 



27 22 aBb 



26 27 ab 



In all the experiments, therefore, there appeared all the 

 forms which the proposed theory demands, and also in 

 nearly equal numbers. 



In a further experiment the characters of floral colour 

 and length of stem were experimented upon, and selection 

 so made that in the third year of the experiment each 

 character ought to appear in half of all the plants if the 

 above theory were correct. A, B, a, b serve again as 

 indicating the various characters. 



A, violet-red flowers. a, white flowers. 



B, axis long. b, axis short. 



The form Ab was fertilised with ab, which produced the 

 hybrid Aab. Furthermore, ciB was also fertilised with ab, 

 whence the hybrid aBb. In the second year, for further 

 fertilisation, the hybrid Aab was used as seed parent, and 

 hybrid aBb as pollen parent. 



Seed parent, Aab. Pollen parent, aBb. 



Possible egg cells, Abab. Pollen cells, a Bab. 



From the fertilisation between the possible egg and 

 pollen cells four combinations should result, viz. : 



AaBb + aBb + Aab + ab. 



