176 



DETAILED SYNTHESIS. 



it will be found to be drawn from the rays of the sun 

 that were condensed by the plant in its albuminized 

 products. 



SECTION III. 



Nervous Tissue. 



134. NERVOUS TISSUE is of two kinds, the gray, 

 cellular, ganglionic, central or active, and the white, 

 fibrous, tubular, or passive parts. 



135. THE GRAY NERVOUS is one form of secretory, 

 but diifers from it in the same general respects as the 

 muscle-cells. 



136. THE GRAY TISSUE DIFFERS by not having any 

 relations to a basement membrane, and by, secreting a 

 substance that is not of use until it is decomposed, and 

 because its use is destructive, or the result of destruction. 



137. THE GRAY TISSUE is COMPOSED of cells, with 

 walls constituted like all cells, filled with a jelly-like 

 granular substance, and also surrounded by a similar 

 substance, in which the cells seem to be very thickly 

 imbedded. 



FIG. 139. 



Fig. 139 represents nervous tissue : 1, two large cells continuous with 

 nerve filaments ; 3, undeveloped cells with nuclei; 2 and 4, a chain of cells 

 connected by filament; B, nerve-cells much enlarged, showing nucleus, its 

 spot, the granules, and one extending point or pole in case of the largest 

 cell ; a a, filaments of white nervous tissue. 



184. Of what kinds ? 

 Describe Fig. 189. 



185. What ? 186. How dues ? 187. How 



