LECT. f.] OF BOTANICAL SCIENCE. 33 



Vegetables, like animals, are organized living 

 bodies. To the superficial observer there appears 

 no difficulty in distinguishing them from animals 

 and fossils ; but those who have examined the sub- 

 ject more minutely, find many obstacles to prevent 

 them from drawing the exact line of distinction be- 

 tween the three kingdoms of Nature. Still, how- 

 ever, vegetables possess peculiarities of structure, 

 habit, and functions, which characterize them; 

 and these are found in every plant. As plants 

 are living beings, so are they also perishable: 

 death, as is the case in animals, may either proceed 

 from innate causes, depending upon their organiza- 

 tion, or be produced by external causes. It is ob- 

 vious to our senses, that vegetables derive nourish- 

 ment from the soil in which they are fixed, and in 

 which they grow, and perfect seed capable of repro- 

 ducing the species. The researches of philosophy 

 have further informed us, that they possess irritabi- 

 lity, by which the nutriment they imbibe is progres- 

 sively moved through every part of their bodies, con- 

 verted into various secretions, and assimilated into 

 the substance itself of the plant; and that, like 

 animals, they produce certain changes on the at- 

 mosphere, and can accommodate themselves to 

 the vicissitudes of heat and cold. In the func- 

 tions of generation, also, plants have many of the 

 peculiarities of the most perfect animals. In stat- 

 ing, however, the close analogy between plants 

 VOL. i. D 



