ELEMENTS OF ORGANIZED STRUCTURE. 243 



elements of that structure the Cells which cannot be 

 divided or wounded without extinguishing their life, 

 and by whose expansion or multiplication all growth 

 takes place. Then will follow an account of the com- 

 plex parts of the plant its Organs which are built up 

 by the juxtaposition of numerous cells. Of these we 

 have one class, viz., the Eoots, Stems and Leaves, whose 

 office is to sustain and nourish the Individual Plant. 

 These may be distinguished as the Vegetative Organs. 

 The other class, comprising the Flower and Fruit, are 

 not essential to the existence of the individual, but their 

 function is to maintain the Race. They are the Repro- 

 ductive Organs. 



CHAPTER II. 

 PRIMARY ELEMENTS OF ORGANIZED STRUCTURE. 



THE VEGETABLE CELL. 



One of the most interesting discoveries that the micro- 

 scope has revealed, is that all organized matter originates 

 in the form of minute vesicles or cells. If we examine 

 by the microscope a seed or an egg, we find nothing but 

 a cell-structure a mass of rounded or many-sided bags 

 lying closely together, and more or less filled with solid 

 or liquid matters. From these cells, then, comes the 

 frame or structure of the plant or of the animal. In the 

 process of maturing, the original vesicles are vastly mul- 

 tiplied and often greatly modified in shape and appear- 

 ance, to suit various purposes ; but still it is always easy, 

 especially in the plant, to find cells of the same essential 

 characters as those occurring in the seed. 



