114 OPE^r AIK GHAPE CULTCEE. 



of other leaves is ap]3lied to tlie increase of size in tlie 

 grapes, and the two leaves that are left ; while on the 

 other hand, the general crop of leaves on the vine will 

 be amply sufficient to prepare those secretions which 

 are to give flavor, color and sweetness to the grapes. 

 This will, perhaps, be better explained by the annexed 

 diagram. 



" Let the line a g represent a lateral vine 

 branch, bearing fruit at b, and leaves Sii cd ef. 

 Suppose six ounces of sap are destined to sup- 

 port this lateral a g, during the summer ; it 

 is evident that, if equally distributed, each d 

 leaf and branch will receive one ounce of sap 

 as its proportion. But \i e f g are removed, 

 it is obvious that the three which remain will ^ 

 liave two ounces each, or double the supply. a 



'' Why, then, it may be asked, not remove c and d 

 also ? because, in that case, b, the bunch of fruit, 

 would have the whole six ounces of sap to itself. The 

 reason why this should not be done is this : if all the 

 leaves on the lateral are removed, there will be no 

 force left upon it wherewith to attract from the main 

 branch the food that belongs to it; for the power 

 which the parts of the plants possess of attracting 

 fluid is in proportion to the amount of their perspira- 

 tion. Now leaves perspire copiously, but the grapes 

 themselves scarcely at all ; whence their gradual con- 



