AEEIAL VINE ROOTS. 141 



which diminishes or prevents colouring; which renders it 

 impossible to ripen wood ; and which deteriorates the quality 

 of the Grape. Hence all good Vine-growers now look more 

 to the temperature of their borders than to its mechanical 

 condition. 



The FoHMATioN OF Aeeiai Roots by Yines is an. immistakeable sign 

 of tiie eoldness of the border. Viaeries may be seen ■with these roots 

 hanging down like beards from the branches ; and these are always 

 followed by bad giapes, unless means are taken to heat the border. 

 The explanation of the phsenomenon seems to be this : — 



The Vine possesses a very strong vegetating power, which is mani- 

 fested whenever sttfflcient heat and moisture are present. It is also 

 well known that if one portion or shoot of a Vine-plant is introduced 

 to an atmosphere congenial to its growth, the buds will push into 

 foliage and shoots ; whilst the rest of the plant, exposed to cold, will 

 not be perceptibly affected, and will contribute nothing to the active 

 vegetation of the branch introduced to heat and moisture. According 

 to circumstances, therefore, vegetation may be active in one part, and 

 at the same time comparatively dormant in another part of the same 

 Vine-plant. If the natural roots are dormant owing to the low 

 temperature to which they are exposed, then unnatural roots wiU be 

 formed by branches if in a state of growth. Moisture favours the 

 formation of these roots ; they shrivel in hot dry weather, but push 

 again on the return of a dull or moist state of the atmosphere. They 

 arise from the shoots being in a highly favourable situation for growth, 

 and the roots in the reverse. The leaves elaborate a quantity of sap 

 proportionate to their size, and to the share which light has had in 

 perfecting their development. Part of this elaborated sap is appro- 

 priated by the above-groxuid portion of the plant. But in ordinary 

 cases, and more especially where a vigorous growth is promoted, there is 

 always a surplus beyond what the stem and its dependencies above 

 ground reqidre, and the proper destination of this is the roots, in order 

 that their increase may correspond with that of the plant above them. 

 But roots in a border five feet deep, and of a clayey nature, wLU be in a 

 temperature little above 40° early in spring. At about 40° water has 

 its greatest density. Under such circumstances any movement in the 

 fluids of the roots must be extremely sluggish ; and were these roots as 

 open to observation as the stem is, there is no doubt they would be 

 found as dormant as a shoot left outside in the cold, compared with 

 another introduced to the heat of a forcing-house. When the roots of 

 Vines are healthy, in proper soil sufficiently warm, their growth proceeds 

 in due proportion to that of the top, but if they are badly conditioned, 

 they can neither act their part nor appropriate their share of the 

 returning juices ; consequently an accumulation of the latter takes 



