THE ROOTS OF GRAPE VINES. 175 



But with vines forced early under glass, the disparity 

 is surprisingly great. The roots, having no artificial 

 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 command, 

 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 organisable matter deposited in its cells is gradually 

 expended in the elongation of the shoots, and the for- 

 mation of leaves and fruit. And such is the extraor- 

 dinary powers of expansion which this matter is en- 

 dued with, that out of a cubical inch of it nature will 

 create a shoot a dozen feet long, and clothe it with vi- 

 gorous 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, while the roots are yet asleep, 



