VEGETABLE PHYSIOLOGY. 3 



of vegetable products is capable of complete disso- 

 lution, without any notable residuum, we are con- 

 strained to admit that the conclusion of the chemist 

 is just. 



When the elemental membrane is uniform in con- 

 sistence and arrangement, it is called cellular ; when 

 varied by being- disposed into tubes and other organs, 

 it is said to be vascular. 



The microscope has assisted us to discover the 

 constitutional fabric of the cellular matter. Each 

 cell is an insulated vesicle, having a thin, pellucid, 

 elastic integument ; originally inconceivably minute, 

 but capable of being distended to a limited size, but 

 in a definite order incident to the plant to which it 

 belongs, and in any direction ; the cells leaning and 

 super-posed on each other, and consequently pressed 

 into the various figures of spheres, spheroids, hexa- 

 gons, or elongated squares or ovals forming the 

 specific structure and organs of the plant. There 

 are also intercellular spaces, which serve for the con- 

 duction of fluids, or depositories of the secretions of 

 the plant. 



A microscope of sufficient magnifying power has 

 too confined a field of view to take in any considera- 

 ble portion of cellular matter, to allow of its being 

 accurately represented by the engraver. Sections, in 

 whatever direction made, never show a regular dis- 

 position of the cells, because they, being of irregular 

 form, and irregularly placed with respect to each 

 other, present, when incised, different forms to the 



