PREFACE. 



This compendious treatise is designed to furnish classes 

 in the higlier seminaries of learning, colleges, and medi- 

 cal schools, as well as private students generally, with a 

 suitable text-book of Structural and Physiological Botany, 

 and a convenient introduction to Systematic or Descriptive 

 Botany, adapted to the present condition of the science. 

 The favor with wjiich the former editions have been re- 

 ceived, while it has satisfied the author that the plan of the 

 work is well adapted to the end in view, has made him the 

 more desirous to improve its execution, and to render it a 

 better exponent of the present state of Botany. In this 

 view, the structural and physiological part of the work, and 

 the chapters on the Principles of Classification and of the 

 Natural System, have been agdin almost entirely rewritten, 

 and such changes made as the advanced state of our knowl- 

 edge required, or the author's continxied experience in 

 teaching has suggested. Tliis has been done without in- 

 creasing the extent of this part of the volume, which, con- 

 sidering the limited time devoted to the study in our col- 

 leges, &c., is found to be as full as is desirable for a text- 

 book. Being intended as a maniial for instruction merely, 

 the Illustrations of the Natural Orders, which form the prin- 

 cipal portion of the systematic part of the work, are brief 



