VEGETABLE PHYSIOLOGY. 9 



it covers the whole surface of the wood of these 

 plants*. 



In all cases the vital principle has the property of 

 resisting extinction for a greater or lesser length 

 of time : of increasing- by expansion or subdivision 

 without destruction, and by oviparous and viviparous 

 reproduction. 



Nutritive Organs. To enable the vegetable being 

 to subsist and perform its various functions, it is 

 provided with organs which are recipients of aqueous 

 or gaseous nutrition attracted from the earth and air. 

 The fibres or spongioles of the subterranean stems, 

 the glands and pores of the cuticle, are the chief 

 inlets of vegetable food ; and by which they receive 

 what is proper, but by which they cannot always 

 reject what is noxious. 



The root fibres are only the recipients of the crude 

 pabulum; this, after being- introduced to the system, 

 becomes assimilated with the inherent qualities of the 

 plant. In vain we search the soil for qualities similar 

 to those found in the roots, stem, leaves, and fruit ; 

 and therefore conclude that in the chambers or vessels 



* It may appear somewhat problematical, or at least an unneces- 

 sary distinction, to assert that any one member of a healthily grow- 

 ing plant possesses more vitality than another; but such distinction 

 is absolutely necessary in the present inquiry, as will appear in the 

 sequel. Here also an apology may be due for the use of new terms : 

 but as they are meant to designate a member which has been 

 hitherto unnoticed, or confounded with others, the introduction of 

 them on this account may be excusable. 



