34 BOTANY 



attracted much study. What the wood is among 

 tissues to the anatomist, that the nucleus is to the 

 cytologist the principal object of his research. Before 

 we turn our attention to the nucleus, however, it is well 

 to notice that in the protoplasm are a number of other 



in. 



FIG. 4. A single cell from typical vegetative tissue, cw, the cell wall, w, the 

 walls of the adjacent cells, showing how they fit into each other to make 

 a honeycomb-like mass. The cell is filled with granular protoplasm, in 

 which lie c, the chromatophores, and ?i, the nucleus. A membrane, m, 

 surrounds the nucleus, which Is of denser composition than the protoplasm, 

 and has several granular masses of a proteid nature in it. 



granules which vary according to the nature of the cell. 

 The commonest of these are starch grains, proteid 

 granules, oil drops, and, in cells from the leaf or the 

 outer part of a young stem, green chlorophyll granules. 

 All these materials are not a fundamental part of the 

 protoplasm, but are a result of its activities. 



In the figure we see a sketch of a typical resting cell. 

 Such is the mature and permanent condition of many 



