30 BREEDING 



instances of the Mendelian phenomenon with which 

 we have dealt, and note the points which they 

 exhibit in common. In each of the five instances 

 the characters were considered in pairs — tall and 

 dwarf, normal and fasciated, and so on. The justi- 

 fication for this is that in every case the two characters 

 of a pair always appertain to the same part of the 

 plant — to the stem, or pod, or seed-coats. And not 

 only so, but to the same feature of a particular part 

 of the plant. Thus tallness of stem and softness of 

 pod do not constitute a pair, because they relate to 

 different parts of the plant. Nor even do tallness of 

 stem and fasciation of stem constitute a pair, because, 

 though both relate to the stem, one relates to the 

 length of the internode and the other to the arrange- 

 ment of the nodes. Thus the two characters which 

 constitute a pair appertain to the same feature of a 

 particular part of the plant. 



A further characteristic of the two members of a 

 pair is that when an individual bearing one of them 

 is mated with an individual bearing the other, the 

 resulting hybrid usually bears one of the pair of 

 characters to the complete exclusion of the other. 

 In the case of tallness and dwarfness, for instance, 

 the hybrid exhibits no trace of the dwarf character ; 

 but in the case of hardness and softness of pods, the 

 pod of the hybrid is a little softer than that of 

 its hard-podded parent. That character of a pair 

 which completely or partially excludes the* other of 

 the pair, in the hybrid, is called the Dominant member 

 of the pair ; the other character is called the Recessive 



