202 



same vegetable, proves that ihere are peculiar vessels 

 for conveying different sorts of uutriment. lu many 

 vegetables some of those vessels are plainly seen full 

 of milky, yellow, or red nutriment. 



Where a secretion is designed to compose a hard 

 substance, viz. the kernel or seed of hard stone fruits 

 it does not immediately grow from the stone, which 

 would be the shortest way to convey nourishment to 

 it. But the umbilical vessel fetches a compass round 

 the concave of the stone, and then enters the kernel 

 near its cone. By this artifice the vessel being much 

 prolonged, the motion of the sap is thereby retard, 

 ej, and a viscid nutriment conveyed to the seed, which 

 turns to a hard substance. 



Let us trace the vegetation of a tree, from the seed 

 io its full maturity. When the seed is sown, in a 

 few days it imbibes so much moisture as to swell 

 with very great force, by which it is enabled both 

 io strike its roots down, and to force its stem out 

 of the ground. As it grows up, the first, second, 

 third, and fourth order of lateral branches shoot out, 

 each lower order being longer than those immediately 

 above them, not only as shooting first, but because 

 inserted nearer the root, and so drawing greater plenty 

 of sap. So that a tree is a complicated engine, which 

 has as many different powers as it has branches. And 

 the whole of each yearly growth of the tree, is pro. 

 portioned to the whole of the nourishment they at- 

 tract. . 



But leaves also are so necessary to promote its 

 growth, that nature provides small, thin, expansions, 

 which may be called primary leaves, to draw nou- 

 rishment to the buds and young shoots, before ffie 

 leaf is expanded. These bring nutriment to them 

 in a quantity sufficient for their small demand; a 

 greater quantity of which is afterward provided, in 

 proportion to their need, by the greater expansion of 

 the leaves. A still more beautiful apparatus we find 

 in the curious expansions of blosscms and flowers^ 



