242 



Plant-Breeding 



from the Provence rose. Greening apple trees often bear 

 Russet apples, and Russets sometimes bear Greenings. 



Bud-varieties may not only come from buds, as 

 grafts, cuttings, and layers, but they sometimes 

 perpetuate themselves by seeds. Now, these seedlings 



are amenable to selec- 

 tion, just the same as 

 any other seedlings are ; 

 the bud-variety, there- 

 fore, may give the in- 

 itial starting-point for 

 plant-breeding. But, 

 more than this, it is 

 sometimes possible to 

 improve and fix the 

 type by bud-selection 

 as well as by seed-se- 

 lection. Darwin cites 

 this interesting testi- 

 mony: "Mr. Salter 

 brings the principle of 

 selection to bear on 

 variegated plants prop- 

 agated by buds, and has thus greatly improved and 

 fixed several varieties. He informs me that at first a 

 branch often produces variegated leaves on one side alone, 

 and that the leaves are marked only with an irregular 

 edging, or with a few lines of white and yellow. To im- 

 prove and fix such varieties, he finds it necessary to en- 

 courage the buds at the bases of the most distinctly marked 

 leaves and to propagate from them alone. By following, 



FIG. 60. Collard. 



