432 Dr. Bell on the Fhyftohgy of Plan!.?. 



are juft, but the reafonings on thefe, by each 

 party, feem equally inconclufive. The analogy 

 of animal nature appears to favour the opinion, 

 that the juice rifes through the wood only, 

 and defcends only through the bark j but this 

 analogy is not complete throughout. The arte- 

 ries are not placed in the internal parts alone, 

 nor the veins in the external, but they accom- 

 pany each other through every part of their dif- 

 tribution. In vegetables, the fap rifes from the 

 roots, but the proper juice defcends tozvards 

 them; in the defcent of the juice, the wood 

 acquires its growth, and abforption is a con- 

 ftant aaion of the leaves. Thefe obfervations 

 render it probable, that there is a circulation 

 of the juices; and if there be, the veflfels which 

 perform it, we may reafonably believe, accom- 

 pany each other through every part of their 



courfe. . 



On the whole we may conclude, that the form- 

 ation and growth of the parts of plants, depend, 

 chiefly, on the vital energy, which is not however 

 exerted, except on the application of ftimulu* 

 We admire the marks of wifdom and defign, 

 which appear in the creation and prefervacioa 

 of vegetables, but we have no reafon to believe 



* Dr Bell from ftveral experiments to which he has 



■ alluded, was of opinion, that many of the manures produce 



their efFefts by ading as Jimuli on the moving fibre^ ot 



vegetables. }• ^' , ^ 



" that 



