

PREFACE. 



NOTWITHSTANDING Vegetable Physiology has 

 engaged the attention of some of the most dis- 

 tinguished Naturalists in Europe, it is still but 

 imperfectly understood. The highest authorities 

 are not yet agreed on the subject, differing in 

 in opinion, as well concerning the motions of the 

 fluids, as in respect of the manner of accretion of 

 what may be called the solids of plants. 



Hitherto the science has been in some degree 

 obscured by the terms employed in its illustra- 

 tion. It has been explained too frequently by 

 references to animal anatomy ; and because there 

 are resemblances in some particulars, a too general 

 idea has been entertained, that the whole of the 



