THE CANADIAN HOllTICULTUIlISr. 87' 



p:FrECTS OF THE SCION UPON THE STOCK. 



BY A. GILCHRIST, GUELPH, ONT. 



Much lias been written about the influence of the scion upon the 

 stock, and mce versa, hut comparatively little has l)een added to our 

 knowledge of the controlling cause, because the experiments and oljser- 

 vations have been so variable and conflicting. I have been gi-aftiug 

 'lie weeping varieties of Ahutiloyis vi^ow the strong upright growing 

 .-orts, the object in view was to obtain miniature weeping trees for the 

 greenhouse, which are novel and pretty. Abutilon Mesopotamicum 

 Varieyatum, which is of a slender weeping habit, grafted about three 

 feet high upon any upright growing variety, makes one of the most 

 beautiful weeping trees. In the south, where it would stand the winter, 

 it would be a decided acquisition. Southern nurserymen might work 

 it up, and give their patrons something new and beautiful. From 

 these experiments in grafting, some curious variations have been pro- 

 iluced. A Mesopotamicum Variegatum was grafted upon a Due de 

 Malako-ff^. Scarcely had the union taken place, when I observed faint 

 markings of a yellowish appearance upon the leaves of the stock belo\Y 

 ilie graft, which soon became as beautiful and distinct as those of a 

 Thompsoni. The experiment was repeated with the same happy 

 results. In one case the leaves became margined "with white, but it 

 oon disappeared, the leaves returning to their original color, while the 

 inottled leaves retained their variation. In my next experiment I 

 reversed the operation. I grafted a Santana upon a Thompsoni, but 

 the* stock had no effect upon the scion. One half of the plant is 

 variagated, the other half green. These two varieties have been growing 

 together for two years with no perceptible change. Due de MalaTco^, 

 having dee])ly cleft or parted leaves, I was anxious to propagate it with 

 those beautiful markings, it being a fine contrast to A. Thompsoni; but 

 after the cuttings were rooted and growing freely, they always went back 

 to their normal condition, showing it had the power to repel the disease 

 which had been communicated to its cells. No doubt many of the varie- 

 gated leaved plants that florists cultivate owe their beauty to some 

 species of disease. From these observations it appears that the down- 

 ward movement of the sap from the scion assumed controlling power, and 

 that the scion has great influence upon the stock; no doubt the stock has 

 a similar influence upon the scion, but not so much as many believe. 



