in Hybridisation 59 



In the tenth generation, for instance, 2 n - 1 = 1023. 

 There result, therefore, in each 2,048 plants which arise in 

 this generation 1,023 with the constant dominant character, 

 1,023 with the recessive character, and only two hybrids. 



THE OFFSPRING OF HYBRIDS IN WHICH SEVERAL 

 DIFFERENTIATING CHARACTERS ARE ASSOCIATED. 



In the experiments above described plants were used 

 which differed only in one essential character*. The next 

 task consisted in ascertaining whether the law of develop- 

 ment discovered in these applied to each pair of differen- 

 tiating characters when several diverse characters are united 

 in the hybrid by crossing. As regards the form of the 

 hybrids in these cases, the experiments showed throughout 

 that this invariably more nearly approaches to that one of 

 the two parental plants which possesses the greater number 

 of dominant characters. If, for instance, the seed plant has 

 a short stem, terminal white flowers, and simply inflated 

 pods ; the pollen plant, on the other hand, a long stem, 

 violet-red flowers distributed along the stem, and con- 

 stricted pods ; the hybrid resembles the seed parent only in 

 the form of the pod ; in the other characters it agrees with 

 the pollen parent. Should one of the two parental types 

 possess only dominant characters, then the hybrid is 

 scarcely or not at all distinguishable from it. 



* [This statement of Mendel's in the light of present knowledge is 

 open to some misconception. Though his work makes it evident that 

 such varieties may exist, it is very unlikely that Mendel could have 

 had seven pairs of varieties such that the members of each pair 

 differed from each other in only one considerable character (wesentliches 

 Merkmal). The point is probably of little theoretical or practical 

 consequence, but a rather heavy stress is thrown on " wesentlich"] 



