PHYSIOLOGY OF TREES. 



269 



the dotted space 7, it contains the rudiments of 

 all the liber, roots, buds, &c. that ever will be 

 produced by the plant ; of this there needs no 

 proof. 



In order to shew that the opinion founded on 

 the above- represented facts is not a mere hypo- 

 thesis, a few proofs may be brought forward, or 

 rather recapitulated, by way of illustration. 



There can be no doubt that all the different 

 parts of a vegetable, developed during its exist- 

 ence, are previously contained in embryo, or state 

 of incipience ; vegetable life, as before observed, 

 being only an expansive power of the essential 

 sap enlarging the vessels which contain it, when 

 acted on at the proper season by a sufficient de- 

 gree of heat ; or, as it would appear in some 

 cases, when the juice by a certain maturation or 

 chemical change of itself takes a kind of fermen- 

 tation, and expands independently of atmospheric 

 heat. Thus many plants whose vernal growth 

 is soon over, recommence it during winter 

 and before the increased heat of spring can affect 



