7S LUTHER BUKBANK 



tame branoliet, are giaoto thai sorpaat even their 

 hybrid parent, not to mention their moderate- 

 •bed grandparents? The fact of this diversity is 

 unqueatkmaUe. It afTordt a lurphae to all who 

 intpeet the trees of this strangely dhrersified 

 fmtemity. 



But how explain it? 



A chie to the explanation is gained when we 

 learn that a California walnut, which, it will he 

 recalled, was a parent form in each of the hybrid 

 strains, is a ttte showing great varisbility in the 

 matter of sise when growing in a state of nature. 

 In the northern and eentral parts of California 

 it is usually a large spreading tree, often with 

 gracefully drooping limbs. Rut farther to the 

 soutJi it becomes a mere shrub, and on the moun- 

 tains and hills about Loa AngeU <>nly a 

 bush. The nut diminishes in size con rs]> ndingly 

 until, in Texas and Mexico, it is scarcely larger 

 than a pea. 



VVboi growing still farther to the south, in 

 New Mexico and Texas, the black walnut is 

 sometimes classified as a different species. 



It appears to me, howe\cr, that these dwarfed 

 southern forms are only varieties that have ac- 

 quired different characteristics through the in- 

 fluence of what for them has proved an unfavor- 

 able environment. In anv event there is no 



