156 PLANTING AND MANAGING 



But with vines forced early under glass, the dispar- 

 ity is surprisingly great. The roots, having no arti- 

 ficial assistance, do not move one minute sooner in 

 the spring, because the branches are made to do so. 

 These latter are produced from, and entirely live on 

 the sap contained in the buds and branches. The 

 first movement of the sap takes place in the upper- 

 most buds; it is there excited and liquified by the 

 heat, the buds then open, and a shoot is the conse- 

 quence. The same process quickly follows with all 

 the other buds downwards; and after the sap of the 

 preceding year's wood is exhausted, the main trunk 

 or stem of the vine becomes affected by the heat, and 

 the moisture stored up in its cells, is, in consequence, 

 gradually melted or liquified, and when in this state it 

 continually sends up nourishment to the parts above ; 

 and if the vine be an established one of some years' 

 growth, it will yield a large supply for even months 

 to come. Indeed, it is the only source of nutriment 

 that the green shoots and leaves have at their com- 

 mand, until the emission of new roots, except that 

 which is presented to them by the moisture of the 

 air by which they are surrounded. The main trunk 

 of the vine being now, therefore, the grand reservoir 

 of supply, the organizable matter deposited in its cells 

 is gradually expended in the elongation of the shoots, 

 and the formation of leaves and fruit. And such is 

 the extraordinary powers of expansion which this 

 matter is endued with, that out of a cubical inch of 

 it nature will create a shoot a dozen feet long, and 

 clothe it with vigorous leaves, and the leaves in their 

 turn will extract from the air as much food as will 

 make that shoot half as long again. From these 

 sources of the branches and leaves of the vine, then, 

 the whole mass of the foliage and also the fruit will 

 derive their nourishment for a long period of time, 



long period of time, entirely on the sap contained in the buds and the 

 small portion of wood left in, in the preceding year. 



The unexampled dryness of the spring was, without doubt, the cause of 

 the non-appearance of new roots at so late a period of the season. 



