III.] SEED -HYBRIDISM AND GRAFT - HYBRIDISM , 93 



known that critical gardeners are always on the alert for 

 such variations. In any house of two hundred roses, all 

 grown from cuttings, the grower will expect to find more 

 than one departure from the type, either in color or 

 freedom of bloom or in habit of plant. Every gardener 

 will recall the " sporting" tendencies of Perle des Jar- 

 dins 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 one hundred and fifty - 

 four named bud -varieties, and remarked at length upon 

 their frequency amongst cultivated plants. (See Plant - 

 Breeding.) This fact of greater bud -variability under 

 cultivation was fully recognized by Darwin, and he re- 

 garded this as one of the strongest proofs that such 

 variation, like seed variation, is "the direct result of 

 the conditions of life to which the plant has been ex- 

 posed." 



In order to extend the proofs of the essential onto- 

 genetic likeness of bud and seminal variations, I will 

 call to your remembrance the fact that the characters 

 of the two phytons may be united quite as completely 

 by means of asexual or graft hybridism as by sexual 

 hybridism. I do not need to pursue this subject, except 

 to say that we now believe that graft -hybrids are rare 

 and exceptional chiefly because the subject has received 

 little experimental attention. Certainly the list given 

 by Focke, and the anatomical researches of Macfarlane, 

 show that such hybrids may be expected in a wide 

 variety of subjects and with some frequency. It is now 

 stated positively by Daniel, as the result of direct ex- 

 periment, that the seeds of cions of certain cultivated 

 herbs which are grafted upon a wild plant give offspring 

 which show a marked return to the wild type. I should 



