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the upper portions of the bunches, and those parts 

 most exposed to the sun's influence, are the first 

 to suffer ; and this, also, goes far towards substan- 

 tiating the assertion, that the shade of the foliage is 

 necessary to the well-doing of grapes. (Gard. Chron. 

 1843, 505.) 



Want of Colour is often a defect of the Black 

 Grape, but not at all necessarily arising from deficient 

 light. The green colour of leaves depends entirely 

 upon the presence either of light or of uncombined 

 hydrogen gas, but vegetable reds, purples, and other 

 colouring matters of fruits, are formed, though less 

 intense, even in a total absence from light. So far 

 from full exposure to light being requisite for the full 

 colouring and ripening of grapes, they never attain 

 these desired qualities so well as when shaded by one 

 thickness of leaf. The colouring matter of all fruit 

 is dependent partly upon the leaves immediately 

 above it, and partly upon the fruit itself ; the neces- 

 sary digestion of the sap being commenced in the 

 one, and perfected in the other. If this digestion or 

 elaboration of the sap is checked by ungenial tem- 

 perature, but more particularly if the crop is too 

 heavy for the vine, or if the leaves, especially above 

 the bunches, are too much thinned, defect of colour 

 will be the very usual consequence to the berries. 



Let it not, therefore, be assumed at any time, that 

 want of colour is caused by the want of sunlight to 



K 



