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PHYSIOLOGY OF TREES. 



Having made some remarks on the physical 

 structure of the plants treated of in the foregoing- 

 pages, it may be expected, perhaps, that some- 

 what should be added on the physiology of trees. 

 This is the more necessary, as it is a part of bota- 

 nical knowledge which is still very obscure : for, 

 though many eminent naturalists have employed 

 their talents in the study and illustration of vege- 

 table phenomena, and though much of the hid- 

 den processes has been brought to light, still the 

 opinions of the learned are conflicting; the sci- 

 ence is mystified by hypothetical schemes of vege- 

 table life and economy, which can neither be 

 proved nor clearly understood. Every lover of 

 the science, however, is indebted to those inde- 

 fatigable individuals, who, by constant observa- 

 tion, dissection, and close examination of the 

 various parts of vegetable conformation, have so 

 clearly shown the etFects, if not the causes, of 

 vegetable life. 



R 



