156 PRINCIPLES OF GARDENING. [CH. V. 



close to the surface of the gi'ound, or they might 

 be even rather below the surface, by scooping out 

 the earth around the stems of the stocks. When 

 planted out, the lowest extremity of the graft should 

 be about four inches below the surface. After two 

 or three years, at the close of June, the soil should 

 be removed, and just above the junction of the graft 

 and stock, with a gouge, one-fourth of the bark 

 removed, by four cuts on opposite sides of the stem. 

 The cuts being deep enough to remove the inner 

 bark, and the wounds covered immediately viixh 

 rich soil, formed of one part putrescent cow-dung, 

 and two parts maiden loam. If kept constantly 

 moist with water, and occasionally ^nth liquid 

 manure, roots will usually be speedily emitted, espe- 

 cially if the place where a bud once was formed 

 be thus kept moist beneath the soil. 



But the stock has some other influence over the 

 sap, besides limiting the quantity of sap supplied to 

 the scion, an influence not only arising from the size 

 of its vessels, but upon its susceptibility to heat. It has 

 a further influence over the scion by the sap becoming 

 more rich, indicated by its acquiring a greater specific 

 gravity in some stocks than in others, during its 

 upward progress. The specific gravity of the sap of 

 a black cluster vine stock on which a black Ham- 

 burgh had been grafted was, when obtained six 

 inches from the ground, 1,003, and at five feet from 



