LUTHER BURBANK 



that their progeny is made relatively sterile. The 

 sterility is not absolute, however, for the few nuts 

 produced germinate readily if planted. 



But another anomaly manifests itself in the 

 characteristics of the seedlings thus produced; 

 for these are the ones that show such extraordi- 

 nary variation in size. 



In the same row, as already intimated, there 

 will be bush-like walnuts from six to eighteen 

 inches in height side by side with trees that have 

 shot up to eighteen or twenty feet; all of the same 

 age and grown from seeds gathered from a single 

 tree. This rate of growth continues throughout 

 life, and the fraternity of dwarfs and giants has 

 been a puzzle to layman and botanist alike. 



These second generation hj-^brids vary as much 

 also in regard to foliage and general characteristics 

 of form and development as in size. Some resemble 

 the California walnut, others the Persian ancestor, 

 and there are scores of variations, the manner of 

 growth of some of which — notably those that 

 trail their limbs along the ground like a gourd or 

 squash — bears scant resemblance to that of any 

 walnut. From this extensive variation, it has 

 been possible to select trees of even more rapid 

 growth than the second generation hybrids, and 

 the field seems to be open for the production, 

 through selection in successive generations, of 



[142] 



