286 



SCIENCE. 



[N. S. Vol. I. No. 11. 



tree I will answer that nectarines have 

 also been produced from peach seeds. The 

 answer to one answers the other. It is 

 true that bud-variations, if we use that 

 term, as we logically must, to denote all 

 variations between phytons, are commonly 

 less marked than seed- variations, but this 

 is only because the conditions of origin and 

 environment of the phyton are less varied 

 than those of the seedling. The phytons 

 originate from one parent, not from two ; 

 and they all grow in very like conditions. 

 But I am convinced that, when we consider 

 the plant individual in the light of evolu- 

 tion, the bugbear of bud-variation vanishes. 

 A good proof that bud-variation and seed- 

 variation are one in kind is afforded by the 

 fact that selection can be practiced for the 

 improvement of forms originating by either 

 means. Darwin was surprised, as he says, 

 to " hear from Mr. Salter that he brings the 

 principle of selection to bear on variegated 

 plants propagated by buds, and has thus 

 greatly improved and fixed several varie- 

 ties. 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 improve 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, with per- 

 severance, this plan during three or four 

 successive seasons a distinct and fixed var- 

 iety can generally be secured." This prac- 

 tice, or similar ones, is not only well known 

 to gardeners, but we have seen that nature 

 selects in the same manner, through the op- 

 eration of the same struggle for subsistence 

 which Darwin so forcibly applied to all other 

 forms of modification . Once given the three 

 fundamental principles in the phylogeny of 

 the phyton, the variation amongst them- 

 selves, the struggle for existence, the capa- 

 bility of perpetuating themselves — an in- 



disputable trinity — and there can no long- 

 er be anj' doubt as to the fundamental like- 

 ness of the bud-variety and the seed-variety.- 



Yet I must bring another proof of this 

 likeness to your miad. It is well known 

 that the seedlings of plants become more 

 variable as the species is cultivated ; and it 

 is also true that bud-varieties are more fre- 

 quent and more marked in cultivated 

 plants. Note, for example, the tendency of 

 cultivated plants to bear variegated or cut- 

 leaved or weeping shoots, and the fact that 

 the colors and doubleness of flowers often 

 vary greatly upon the same plant. Many of 

 our best known roses, carnations, chrysan- 

 themums, violets and other garden plants 

 originated as bud-sports. This fact is so well 

 known that critical gardeners are always on 

 the alert for such variations. In any house 

 of 200 roses, aU grown from cuttings, the 

 grower will expect to find more than one de- 

 parture from the type, either in color or free- 

 dom of bloom or in habit of plant. Every 

 gardener will recall the ' sporting ' tenden- 

 cies of Perle des Jardins rose, and the fact 

 that several commercial varieties have 

 sprung from it by bud-variation. As early 

 as 1865 Carriere gave a descriptive list of 

 154 named bud-varieties, and remarked at 

 length upon their frequency amongst culti- 

 vated plants. This fact of greater bud- 

 variability under cultivation was fully 

 recognized by Darwin, and he regarded this 

 as one of the strongest proofs that such va- 

 riation, like seed- variation, is " the direct 

 result of the conditions of life to which 

 the plant has been exposed." 



In order to extend the proofs of the es- 

 sential ontogenetic likeness of bud and semi- 

 nal variations, I wUl call to j^our remem- 

 brance the fact that the chai'acters of the 

 two phytons may be united quite as com- 

 pletely by means of asexual or graft hybrid- 

 ism as bj' sexual hybridism. I do not need 

 to pursue this subject, except to say that 

 we now believe that graft-hybrids are rare' 



