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great pains to difcover two kinds of vcflcls in the leaves of trees and 

 plants in order to al'certain, whether there was any circulation in 

 leaves, but I never could lee more than one fpecies of velTels, namely 

 thofe tluit convey the nutritive juices to .the feveral parts. 



But, if we confider, that not only the leaves of trees, but alio their 

 fruits, do not need any other than thofe nutritive juices, which are 

 requifite to bring them to perfe6lion, we fliall not wonder that when 

 at a date of maturity, they are, as it were, fpontaneoufly loofened 

 or fliaken off from the tree, without the lead appearance of having 

 been broken off; nay, that part of the flalk which was originally 

 united to the tree, will appear as fmooth as if, with its multitude 

 of veffels, it never had been joined to it. 



In a word, I will venture to adert, that neither the wings of the 

 before mentioned flying infects, nor the leaves or fruit of trees, 

 require that kind of circulation of the juices, which we have been 

 confiderine:. 



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