BOOK I. 



ORGANOGRAPHY; OR STRUCTURAL A^'D MORPHOLOGICAL 

 BOTANY. 



The most superficial examination by the unassisted eye of any 

 of the more highly developed and organized plants enables us to dis- 

 tinguish various parts or organs, as root, stem, leaves, and the 

 parts of the flower. A similar examination of plants of lower 

 organization and development presents to our notice either the 

 same organs, or organs of an analogous nature to those of the 

 higher plants. By a more minute examination of these several 

 organs by the microscope, it will be found that they are made 

 up of others of a simpler kind, in the form of little membranous 

 closed sacs, called cells, and tubular bodies, of various forms, 

 sizes, and appearances, and combined together in various ways. 

 Hence, in describing a plant with reference to its structure, we 

 have two sets of organs to allude to, namely, the compound 

 organs or those which are visible to the naked eye, and the 

 elementary organs or structures of which they are composed. A 

 knowledge of these elementary structures, or building materials 

 of the plant, is absolutely essential to a complete and satisfac- 

 tory acquaintance of the compound organs, but, previous to de- 

 scribing them, it will materially assist our investigations if we 

 give a general sketch of the compound organs, and of the plants 

 which are formed by their union. According to the number 

 of these compound organs, and the greater or less complexity 

 which they exhibit, so, in a corresponding degree does a plant 

 vary in these particulars. Hence, we find plants exhibiting a 

 great variety of forms. That part of Botany which has for its 

 object the study of these forms and their component parts is 

 called Morphology. 



