76 Mendel's Experiments 



or 



AB + AM + AaB + AaBb + ABb + Ab + AaBb + Aab + 

 AaB 4- AaBb + aB + aBb + AaBb + Aab + aBb + ab = AB + 

 Ab + aB + ab + 2 ABb + 2aBb + 2AaB + 2 Aab + AaBb*. 



In precisely similar fashion is the developmental series 

 of hybrids exhibited when three kinds of differentiating 

 characters are conjoined in them. The hybrids form eight 

 various kinds of egg and pollen cells ABC, ABc, AbC, 

 Abe, aBC, aBc, abC, abc and each pollen form unites 

 itself again on the average once with each form of egg cell. 



The law of combination of different characters which 

 governs the development of the hybrids finds therefore its 

 foundation and explanation in the principle enunciated, 

 that the hybrids produce egg cells and pollen cells which 

 in equal numbers represent all constant forms which result 

 from the combinations of the characters brought together 

 in fertilisation. 



EXPERIMENTS WITH HYBRIDS OF OTHER SPECIES OF PLANTS. 



It must be the object of further experiments to ascertain 

 whether the law of development discovered for Pisum 

 applies also to the hybrids of other plants. To this end 

 several experiments were recently commenced. Two minor 

 experiments with species of Phaseolus have been completed, 

 and may be here mentioned. 



An experiment with Phaseolus vulgaris and Phaseolus 

 nanus gave results in perfect agreement. Ph. nanus had 

 together with the dwarf axis simply inflated green pods. 

 Ph. vulgaris had, on the other hand, an axis 10 feet to 



* [In the original the sign of equality ( = } is here represented 

 by + , evidently a misprint.] 



