PREFACE. VU 



stitute for the Linnaean system : and, indeed, its gen- 

 eral prevalence to the present time, after so long a 

 trial, is almost a tacit acknowledgment of its conve- 

 nience, if not of its superiority over other systems of 

 arbitrary arrangement ; for, however natural groups 

 or orders of plants may be in their mutual affinities, 

 all classes and higher divisions of the vegetable sys- 

 tem are now confessedly artificial, even among the 

 warmest advocates for a natural method. 



Of the second part of this work I have but little to 

 say, as it is chiefly an abridgment of a very laborious 

 and useful work on Vegetable Physiology, making 

 part of a course of Lectures by Mr. Anthony Todd 

 Thompson, published in London, and forming, in the 

 estimation of the author, one of the best treatises on 

 the subject which has appeared in the English lan- 

 guage. But a very small part of the volume has been 

 introduced, and that only on the general composition 

 of vegetables, and the structure of the principal parts 

 of the plant our limits not permitting any thing like a 

 general system of vegetable physiology. If what has 

 been given should awaken a taste for additional know- 

 ledge on the subject, the following works may be con- 

 sulted with advantage. Greiv, on the Anatomy of 

 Plants ; Malpighi, Anatome Plantarum ; Rudolphi, 

 Anatomie der Pflanzen ; Kieser, Memoire sur l'Or- 



