PART V. 



ANATOMY AND PHYSIOLOGY otf VEGETABLES. 



THIS comprehends an account of the internal or- 

 gans, and the functions they perform. 



Plants are organic bodies, containing cells, vesicles* 

 absorbents, tubes, &c. which being disposed in regular 

 order and qualified with the principle of vitality, arc 

 the laboratory in which nature produces the phenome- 

 na of vegetation. 



Plants as well as animals then are endowed with the 

 principle of life or vitality, a principle which minerals 

 do not possess ; they are living organized beings." 



If it be asked what this principle of life or vitality is, we must 

 own our complete ignorance. We know it, as we know its omnip- 

 otent Author, by its effects. 



The effects of vitality are stupendous beyond conception, in the 

 operations constantly going on in every organized body, from our 

 own elaborate frame to the humblest moss or fungus. 



Those different fluids which compose the eye, so fine and trans- 

 parent, separated from each other by membranes as fine, all retain 

 their proper situations (though each fluid individually is perpetu- 

 ally removed and renewed) for sixty, eighty, or an hundred years 

 or more, while the principle of life remains. 



So do the infinitely small vessels of an almost invisible insect, 

 the fine and pellucid tubes of a plant, all hold their destined 

 fluids, conveying or changing them according to fixed laws, but 

 never permitting them to run into confusion so long as the vital 

 principle anftnafes their various forms. But no sooner does death 

 happen, than witlwut any apparent alteration of structure, any ap- 

 parent change in the ir material configuration, all is reversed. The 

 eye loses its form and brightness ; its membranes let go their 

 contents, which mix in confusion, and thenceforth yield to the 

 laws of chemistry alone. Just so it happens, sooner or later, to 

 the other parts of the animal as well as vegetable frame. 



Chemicai changes, putrefaction and destruction immediately 

 follow the total privation of life, the importance of which instant* 

 ly becomes evident when it is no moret 



