204 PLANT-BREEDING 



On the farm at Sebastopol I saw long rows of Calla, all 

 richly flowering and showing an astonishing amount of 

 variability. High and dwarf forms and all their intermed- 

 iates, large and small cups, varying from white to yellow 

 and not rarely spotted, leaves of all forms and color, some 

 hairy and some smooth, some of a dark green and others 

 spotted or even striped with white, more or less purple and 

 brown, and with many other differences, too many to be here 

 summarized. Add to this various degrees of hardiness and 

 frost resistance, a prolonged period of blooming, rapid 

 propagation by means of side shoots, and other (qualities 

 that may cause the varieties to become some day quite 

 ordinary garden plants and you may have some idea of the 

 almost inexhaustible range of variability. If we now ask 

 whence this large group of characteristics comes, the answer 

 is readily given by the history of the culture, but whenever 

 we ask for the ancestry of one single striking plant, it is 

 not historically known, but must be derived from its apparent 

 affinity to some among the ancestors of the whole family. 



Burbank began his work on the Calla with the ordinary 

 cultivated species, which is almost everywhere known under 

 its names of Calla athiopica or Richardia africana. He 

 secured the commercial varieties, including some dwarfs and 

 some spotted forms, hybrids whose parentage seems to have 

 been forgotten. From their crosses he secured a fragrant 

 variety with a pleasing perfume. It is of a semi-dwarf 

 stature and is one of the most freely-blooming kinds within 

 the old range of forms. Under the name of "Fragrance" 

 it has found general recognition, especially among eastern 

 florists. The range of possibihties in this group was, how- 

 ever, very hmited and seemed in the main to be exhausted. 

 Therefore, Burbank decided to widen it by the introduction 

 of new species. Here one of the most striking features of 

 his method may be observed. If we consult the history of 



