16 VEGETABLE LIFE. 



animals, it is active or dormant ; in the one case 

 constantly progressing- as from the centre of a circle, 

 diverging every way around: or, if inert, reposing 

 safely in a kind of slumber, and imparting a con- 

 servative principle to the parts immediately sur- 

 rounding it. 



In seed it remains dormant, but without extinction, 

 for ages. This is attributable to the preservative 

 character of the coverings its intrinsic qualities 

 and to the absence of those atmospheric influences, 

 which, when present, effect the development of the 

 plant. 



Whole plants, or parts of plants, if defended from 

 the influence of air or extreme changes of weather, 

 may lie inert and uninjured for many months, or 

 years; and, when replaced in a natural situation, 

 recommence growth and exhibit every vegetable 

 function. 



From these instances it is quite obvious that vege- 

 table life is a real, though only a passive principle. 

 Real in its power of preservation even whilst asleep ; 

 and passive by virtue of its excitability, and the ex- 

 pansive nature of the frame in which it is contained. 



Vegetable life commences and is progressive under 

 every degree of heat between the freezing point, and 

 150 of Fahrenheit. It is arrested when the tempera- 

 ture is at or below 32. All vegetation suifers during 

 frost, and many plants are utterly destroyed by it. 

 This happens in consequence of the juices becom- 

 ing crystallised, by which the cells are disrupted, and 

 the healthy organisation destroyed. Plants having an 



