THE FRAGRANT CALLA 33 



a magnifying-glass showed the pollen grains of 

 one form to be round and the pollen grains of the 

 other form to be oval. This insignificant differ- 

 ence, however, is full proof that the plants belong 

 to different strains. 



The union of the divergent strains seemingly 

 brought together pairs of hereditary color-factors 

 if we hold to the Mendelian explanation that 

 had been separated and hence had gone unmated 

 for an indefinite number of generations. 



In the same way, we may suppose. I had 

 brought together, through a happy chance, in the 

 course of these breeding experiments with the 

 calla, two strains that bore complementary odor- 

 factors, the union of which released and made 

 tangible the latent quality of perfume-bearing, 

 which, in all probability, no calla of either strain 

 had outwardly manifested for hundreds or per- 

 haps for thousands of years. 



Xo race is perfected 720 living 

 thing is freed from the struggle for 

 existence. 



Vol. 2 Bur. B 



