in Hybridisation 353 



the parental forms, the two others present combinations 

 between the conjoined characters A, a, B, b, which com- 

 binations are likewise possibly constant. Four classes 

 appear always twice, and are constant in one character and 

 hybrid in the other. One class appears four times, and 

 is hybrid in both characters. Consequently the offspring 

 of the hybrids, if two kinds of differentiating characters are 

 combined therein, are represented by the expression 



This expression is indisputably a combination series in 

 which the two expressions for the characters A and a, B 

 and b are combined. We arrive at the full number of the 

 classes of the series by the combination of the expressions : 



Expt 2. 



ABC, seed parents ; abc, pollen parents ; 



A, form round ; a, form wrinkled ; 



B, albumen yellow ; b, albumen green ; 



C, seed-coat grey-brown. c y seed-coat white. 



This experiment was made in precisely the same way as 

 the previous one. Among all the experiments it demanded 

 the most time and trouble. From 24 hybrids 687 seeds 

 were obtained in all : these were all either spotted, grey- 

 brown or grey-green, round .or wrinkled^. From these in 

 the following year 639 plants fruited, and, as further 

 investigation showed, there were among them : 



8 plants ABC 22 plants AB Cc 45 plants ABbCc 

 14 ABc 17 AbCc 36 aBbCc 



9 AbC 25 aBCc 38 AaBCe 

 ii Abe 20 abCc 40 AabCc 



8 aBC 15 ABbC 49 AaBbC 



10 aBc 1 8 ABbc 48 AaBbc 



10 ,, abC 19 ,, aBbC 



7 ,, dbc 24 aBbc 



14 AaBC 78 AaBbCc 



1 8 AaBc 



20 AabC 



1 6 Aabc 



* [Note that Mendel does not state the cotyledon : colour of the first 

 crosses in this case; for as the coats were thick, it could not have been 

 seen without opening or peeling the seeds.] 



L. H. 23 



