6 VITAL ACTIONS. 



when we have thoroughly studied the phenomena of 

 vegetation, are we able to discover any analogies, ex- 

 cept of a general and theoretical nature, between the 

 animal and vegetable kingdoms. It is therefore ne- 

 cessary that plants should be studied by themselves, 

 as an abstract branch of investigation, without at- 

 tempting to reason as to their habits from what we 

 know of other organic beings ; and consequently we 

 are not, in this part of Natural History, to acknow- 

 ledge any theory which is not founded upon direct 

 experiment^ and proved by the most satisfactory 

 course of inquiry. 



10. In discussing this subject, it will be most con- 

 venient for my present purpose, if I divide the mat- 

 ter into the heads of, 1. Germination ; 2. Growth by 

 the Eoot ; 3. Growth by the Stem ; 4. Action of the 

 Leaves ; 5. Action of the Flowers ; and, 6. Matura- 

 tion of the Fruit. By this means the life of a plant 

 will be traced through all its principal changes, and 

 it will be easy to introduce into one or other of these 

 heads every point of information that can be interest- 

 ing to the cultivator ; who will be most likely to seek 

 it in connexion with those phenomena he is best 

 acquainted with by their effects. 



