GENERAL TEXTURE OP PLANTS. 13 



or perhaps from mere water and air. The 

 most different and discordant fluids, sepa- 

 rated only by the finest film or membrane, 

 are, as we have already observed, kept per- 

 fectly distinct, while life remains; but no 

 sooner does the vital principle depart, than 

 secretion, as well as the due preservation of 

 what has been secreted, are both at an end, 

 and the principle of dissolution reigns abso- 

 lute. 



Before we can examine the physiology of 

 vegetables, it is necessary to acquire some 

 idea of their structure. 



JVIuch light has been thrown upon the 

 general texture of Vegetables by the micro- 

 scopic figures of Grew, Malpighi and others, 

 repeated by Dr. Thornton in his Illustration 

 of the Linnsean System, but more especially 

 by the recent observations and highly mag- 

 nified dissections of M. Mirbel. See his 

 Table of Vegetable Anatomy in the work 

 already mentioned. From preceding writers 

 we had learned the general tubular or vas- 

 cular structure of the vegetable body, and 

 the existence of some peculiar spirally-coated 

 vessels in many plants. On these slender 



