164 LUTHER BURBANK 



the other as regards any individual character that 

 could be segregated and classified. 



Neither as to size and form of plant stalk, nor 

 as to leaf, nor as to the fruit itself, was there clear 

 prepotency or dominance of one parent over the 

 other. 



If there was an exception to this it was per- 

 haps that the fruit tended to be borne in clusters, 

 as in the case of the currant tomato, rather than 

 singly or in small groups as with the tree tomato 



Attention is called to these diversities because 

 it is well to emphasize anew that the phenomena 

 of the clear segregation of "unit" characters, with 

 the exhibition of dominance and recessiveness 

 which the pea with which Mendel experimented 

 manifests so beautifully, and which we have seen 

 manifested in the characteristics of numerous 

 other plants is not a universal phenomenon 

 that the plant experimenter may confidently ex- 

 pect always to discover and use as an easy and 

 simple guide along the path of plant develop- 

 ment. Different species of plants, different 

 varieties, even different individuals show diver- 

 sity as to the extent to which the so-called unit 

 characters are segregated and mutually com- 

 bined or antagonized, and as the reader who has 

 followed the story of various plant developments 

 already outlined is clearly aware. 



