LUTHER BURBANK 



different to the conditions of moisture and a 

 moderate degree of cold does not in the least 

 discourage them. 



The contrast in this regard between the newer 

 hybrids and the earlier yellow varieties is very 

 striking. They furnish an illustration of the added 

 vitality that may come through hybridization. 



The original yellow calla is confined to a lim- 

 ited area in the sub-tropical regions of South 

 Africa. Its pure-bred descendants, as we have 

 seen, retain the sensitiveness of the parent. But 

 the selected hybrids, while retaining the yellow 

 color of the African plant, have acquired from 

 their other parental strains a degree of hardiness 

 that adapts them to our climate, and at the same 

 time have received increments of vigor that noth- 

 ing but hybridization appears to give. 



As to the later point, I may mention a sport 

 that appeared among my white callas, in the form 

 of a plant that grew to gigantic size. The sport 

 appeared among the seedlings of the common calla 

 but doubtless represents a natural cross between 

 different strains of this species. 



The plant bore its flowers on stems sometimes 

 six feet or even more in height. The foliage was 

 of corresponding size, and the flowers almost pro- 

 portionately immense. 



The new sport was named the Giant Calla. 



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