FLOWER POSSIBILITIES 205 



berry and the raspberry, were interbred. In such 

 a case as that the pollen and the ovule bring 

 groups of hereditary factors that are widely 

 divergent. And even in the usual cases of cross- 

 fertilization within a species, where pollen of one 

 plant is brought to the pistil of the flower of a 

 neighboring plant, there is a certain opportunity 

 for the mingling of diverse hereditary fac- 

 tors, inasmuch as no two plants are precisely 

 alike. 



But in the case of our Heuchera, the flowers 

 were self- fertilized, or at most the pollen from one 

 flower was transferred by an insect to the pistil 

 of a neighboring flower on the same stalk, and 

 thus it was arranged that both hereditary strains 

 should be as nearly identical as is possible. 



In the essential matter of the form of leaf, the 

 hereditary factors brought by the pollen grains 

 called for a leaf with crinkled edges; and the 

 hereditary factors carried by the ovules had the 

 same specifications. So there was the best pos- 

 sible chance that the offspring would reproduce 

 or accentuate the parent character. 



And yet the results show that there must have 

 been a certain amount of diversity among the 

 various pollen grains and ovules even of the 

 single plant, inasmuch as the plants that grew 

 from its seed were diversified in character. 



