steuart's planter's guide. 



255 



tually ; and no one can precede another, either m 

 the order of natiu'e, or of thne. Thus, hi an ani- 

 mal, the digestive, and the ahsorhent, the sanguin- 

 eous, the respiratory, and the nervous systems are at 

 once relative and correlative. In like manner, in a 

 plant, the same reciprocal proportion is found to hold 

 between the roots and the stem, the branches and 

 the leaves : Each modifies and determines the ex- 

 istence of all the others, and is equally affected by 

 all in its tmii. And as their several parts, by 

 means of their union, constitute the organic whole ; 

 and as their functions, by the same means, realize 

 the complem.ent of life, which the plant or animal 

 exhibits ; it is evident, that every living individual 

 is a necessary system, in which no one part can be 

 affected, without affecting the other parts, and 

 throughout which there reigns an intimate sympa- 

 thy, and a complete harmony of perfection and im- 

 perfection. 



" Further ; The external conditions of this inter- 

 nal development of plants and animals^ are Food, 

 Air, and Heat ; while Light seems to be a peculiar 

 condition, indispensably necessary to plants. Where 

 any one of these conditions is not supplied, the ex- 

 istence of life, whether animal or vegetable, becomes 

 impossible ; where it is insufficiently supplied, life is 



