THE CELL AND CELL DIVISION 



35 



of complex framework or fine network of irregularly woven 

 paths along which are scattered minute granules called micro- 

 somes. The spaces or meshes of this spongioplasmic network 

 are filled with the less dense ground substance or cell sap, called 

 also the hyaloplasm, paraplasm, or inter filar substance. The 



en 



FIG. 16. Diagram of a typical cell, a, aster; c, centrosome (centriole) ; 

 ch, chromatin; cr, chromidia; cs, centrosphere ; d, deutoplasmic granules; en, 

 endoplasm; ex, exoplasm (cortical plasm); hy, hyaloplasm; k, karyosome; I, linin 

 network; m, cell membrane; n, nucleus; nra, nuclear membrane; o, nucleolus; 

 p, plastids; sp, spongioplasm; v, fluid vacuoles (metaplasm). 



actual relation of these two kinds of substances varies in 

 different kinds of cells or even at different times in the same 

 cell. A frequent arrangement is that of a reticulum just 

 described, in which the spongioplasm is definitely fibrous, 

 forming a felt-work holding the more fluid hyaloplasm. In 

 other cells, or at other times, protoplasm has a distinctly alveolar 

 structure resembling a fine emulsion. Here the hyaloplasm is 



