THE CANNA AND CALLA 49 



But while the new hybrids outwardly resemble 

 some of the early varieties developed by selection, 

 they showed their inherent difference in that they 

 are exceedingly easy to cultivate, whereas the 

 earlier ones were subject to decay without appar- 

 ent cause at any season of the year. The new 

 hybrids are hardier, and can be raised much more 

 readily. They will grow out-of-doors in any mild 

 climate, and require scarcelj' more attention than 

 so many potato plants. They are reasonably in- 

 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 crossing 

 and selection. 



The original yellow calla is confined to a lim- 

 ited area in the subtropical 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. 



