SECT. I. INTRO-SUSCEPTION. Qf 



selves and of artificial waterings may be accounted 

 for upon the same principle ; for they have not 

 always penetrated to the root when they are found 

 to have given freshness to the plant ; and indeed 

 many plants will thrive merely by having their 

 leaves kept moist, though no water should reach the 

 root at all. The same thing might be said of the 

 immersed Fuel, many of which being totally des- 

 titute of root, and constituting merely a sort of 

 frond or leaf, absorb the nourishment necessary to 

 their support by the whole of their surface. The 

 moisture then entering the plant as a food is taken 

 up by means of the absorbent pores of the epi- 

 dermis, not only of the root and leaf> but often, as 

 it is to be believed, of the other parts of the plant 

 also, at least when they are in a soit and succulent 

 state. 



But by what means do the gaseous fluids enter Elastic 



n . , 



the plant? From what has been already ascertained be inhaled 

 concerning the vegetable structure, it follows un- 

 avoidably that the gases which may be inhaled as 

 a food must enter the plant in a manner similar to 

 that of moisture, that is, they must also pass 

 through the pores of the epidermis. Perhaps the 

 pores by which moisture is absorbed are fitted also 

 for the inhalation of air; but this cannot be re- 

 garded as altogether certain ; if it is not rather 

 altogether certain that each of the two fluids enters 

 the plant by a peculiar set of pores. Or by dif- 



Bonnet has shown that most leaves absorb mois- 



VOL. II. H 



