155 



PART II. 



PHYSIOLOGICAL BOTANY. 



CHAPTER I. 



VITAL PROPERTIES AND STIMULANTS. 



VEGETABLE LIFE (139.)' PROPERTIES OP TISSUES (141.). 



KNDOSMOSE (144.). VITAL PROPERTIES (145.). STIMU- 

 LANTS TO VEGETATION (152.). 



(13.Q. bis.) Vegetable Life HITHERTO we have been 

 occupied with the forms only which the various organs 

 of plants assume, and the manner in which they may 

 be considered to be mutually related. We have been 

 examining merely some of the details of that exquisite 

 mechanism by means of which the vital principle is 

 enabled to act and may be acted upon ; and thus 

 produce all the varied and complicated results which 

 the phenomena of vegetation present. In this second 

 part of our treatise, we propose to examine the vegetable 

 machinery in a state of action, and to search for 

 indications of those laws by which vegetable life 

 enables the organic bodies to which it is united to 

 grow and multiply. It would be an unnecessary 

 waste of words to offer any proof that plants are 

 organised bodies endowed with life. No one is so 

 little observant, as to be ignorant of the more ge- 

 neral phenomena of vegetation, that plants originate 

 from seed, that they are gradually developed, and, 



