ACTION OP THE VESSELS OF VEGETABLES. 73 



various products which have been spoken of, and innu 

 merable others, we can only conjecture. 



Some of the imagined operations are strikingly set 

 before us in a picturesque passage which may form a fit 

 conclusion to this chapter. 



&quot; The vessels of vegetables have the same wonderful, 

 and seemingly intelligent power of selection, that exists 

 in the vessels of animals. They are thus enabled to 

 select from the compound circulating sap, what each set 

 of vessels requires, to construct the tissue which each has 

 in charge. One set selects materials for the alburnum, 

 another for the bark, another for the leaf and the leaf- 

 bud ; another forms the fruit-bud, and ultimately builds 

 up the fruit. One set constructs the woody-fibre, another 

 set the starch, another the gum, another the jesin, another 

 the bitter principle, another the sweet and nutritious 

 juices, another the poisonous elements. One set forms 

 from the sap, the coloring matter that blushes or glows 

 in the petals of the flowers, and the coverings of the fruit. 

 Another selects, atom by atom, the lime that enters into 

 the composition of the grain of wheat; another set 

 weaves the covering for this same grain, from the woody 

 fibre. Another set deposits the fatty elements, and 

 arranges them in layers, around the starch and sugar 

 and lime, of which the kernel of corn is built up. Thus 

 every tissue and every product of vegetable life are 

 formed by innumerable vessels, from the descending 

 sap.&quot;* 



* See a beautiful &quot;Prize Essay&quot; upon Manures, by JOSEPH REYNOLDS, 

 M. D., of Concord, Mass. 



