52 ON VEGETABLE PHYSIOLOGY. 



systematic works on botany, and which will form 

 a part of your reading, should your attention be 

 more particularly directed to its study. 



By a vegetable, we mean an organized sub- 

 stance possessing vitality, power of growth and 

 re-production, deriving its nourishment directly 

 from the earth, or from substances in which earthy 

 matter is more or less present, but without per- 

 ceptive powers, or voluntary locomotion ; the two 

 latter properties belonging exclusively to animals, 

 and forming the principal line of distinction. 



Hence every living substance of the above de- 

 scription, whether it be a tree, a shrub, a herb, a 

 grass, or a flower, is in reality a vegetable; and the 

 whole, taken together, constitutes what has been 

 termed the vegetable kingdom, Of these, nearly 

 one hundred thousand species, each possessing its 

 own peculiarities, form and laws, have already 

 been discovered, and the list is annually increas- 

 ing. The subject therefore, independently of its 

 practical application, is one of deep interest and 

 importance ; and the more it be examined, the 

 greater field we find for enquiry, and an increased 

 reason for admiring the contrivance, wisdom, and 

 benevolence, by which this interesting portion of 

 the universe has been regulated. 



To describe each particular organ of a vegeta- 

 ble, is denominated the anatomy, and to enter 

 upon the functions of those organs with the re- 

 sults, the physiology of vegetables. To explain 



