MUTUAL INFLUENCE OF THE STOCK AND GRAFT. Ill 



Pennsylvanicum) when grafted on stock of the sycamore maple {Acer 

 pseudo-plotanus) increased to four times its natural size. 



J. Sisley says: ' " Tea roses, and particularly the more delicate varieties, 

 acquire more vigor when grafted on the seedling briar than on their own 

 roots." 



These instances of greater vigor in grafted plants can in most cases be 

 attributed to the vigorous stocks used. Darwin, however, is inclined to 

 believe that the mere fact of grafting on any different stock tends to give 

 increased vigor. After discussing the vigor gained by changing seed, he 

 says: 2 "Something of this kind apparently occurs in grafting and bud- 

 ding fruit trees; for, according to Mr. Abbey, grafts or buds generally 

 take on a distinct variety, or even species; or, on a stock previously grafted, 

 with greater facility than on stocks raised from seeds of the variety which 

 is to be grafted ; and he believes this can not be altogether explained by 

 the stocks in question being better adapted to the soil and climate of the 

 place. It should, however, be added that varieties grafted or budded on 

 very distinct kinds, though they may take more readily, and grow at first 

 more vigorously than when grafted on closely allied stocks, afterward 

 often become unhealthy." 



Not only may a vigorous stock give increased vigor to the graft, but, 

 conversely, a vigorous graft may cause the stock to grow more than it 

 would if it had not been grafted. Thus, M. T. Masters 3 says that a 

 quince stock, on which a strong-growing pear has been grafted, may be 

 made to produce within a given time a larger amount of wood than any 

 ungrafted quince would do in the same time. E. H. Hart of Florida 

 states:* "Wherever I have worked stocks of the sour orange with the 

 lemon, which latter is of more rapid growth, the stocks increased in thick- 

 ness very much faster than when grafted with the sweet orange." 



Peter Grieve of England, relates 5 a remarkable example of the influ- 

 ence of the scion upon the stock: "An old Ribston Pippin apple tree, a 

 much esteemed variety, is known to succeed indifferently on some kinds 

 of soil and in some situations. The tree in question occupied what may 

 have been considered a favorable position, viz., the west end of a south 

 wall in an old garden. The original soil was not of good quality, being 

 light and gravelly, and the tree, though annually producing some good 

 fruit, was at the same time in an unhealthy and cankered condition. It 

 covered, however, a large portion of the wall, and, being trained horizont- 

 ally, each alternate rod or branch was removed to within a few inches of 

 the stem, and these were grafted with scions of a strong-growing culinary 

 apple, named Alexander, which grew rapidly; and the intention was to 

 have, in the course of a few years, removed the remaining branches of the 

 Hibston and regrafted them also with the sort just named. This inten- 

 tion, however, was very willingly abandoned, as the portion left of the 

 Pvibston improved so greatly in condition that it was gladly retained. * 

 * * In the case of the grapevine some of the finest and best finished 

 bunches I have seen of the Muscat Hamburgh and Mrs. Pince's Black 

 Muscat were produced upon rods which grew upon a stock that also sup- 

 ported rods of the Trebbiano and the Alicante varieties. It is thus evi- 

 dent that the feeding power of the roots of plants is regulated by the 



1 The Garden, Vol. XXV, 1884 p. 62. 



2 Animals and Plants Under Domestication, Vol. II, p. 180. 



3 Gardeners' Chronicle, 1872, p. 322. 



i Transactions Massachusetts Horticultural society, 1880, p. 175. 

 5 The Garden, Vol. XXI, 1882, p. :m. 



