EPIDERMIS, ETC. 



between the cells of such tissue which vary in form, size, 

 and purpose, as the terms employed designate. 



CHAPTER III. 



ORGANOGRAPHY. 



29. We have spoken of the elementary structures, 

 out of which all the other more compound organs of 

 plants are formed, and of which compound structures 

 themselves we have now to speak. 



Epidermis, 8?c. 



30. The epidermis is a thin layer composed of cellular 

 tissue, the walls of whose cellules are closely approxi- 

 mated to each other, and form by their union what are 

 termed reticulations. 



31. This cellular layer exists externally over all 

 portions of the surface of 



plants, save in two places 

 only. 



32. These places are the 

 extremities of the radicles, 

 (or fibres of the root) and 

 the stigmatic surface, (or 

 extremity of the female or- 

 gan of generation) in which 

 the external covering is 

 somewhat modified. 



33. According to some, the epidermis, or skin of a 

 plant, is covered externally by a thin membrane called 

 cuticle; but it is highly probable that this cuticle is 



