STRUCTURE OF CELL. 

 Fig. lo.— Nervous Tissues. 



2 



I. Transverse section of small nerve. 2. Multipolar nerve-cell. 

 * 3. Bipolar nerve-cell. 



Structure of the Cell. — We may now pass from the 

 external form of a cell to its internal structure. Inside the 

 cell membrane is the cytoplasm or cell-protoplasm. Lying 

 in the cytoplasm is the nucleus surrounded by a delicate 



Fig. II.— Diagram of a Cell. (After Carnoy.) 



Chromatin. 



Nucleolus. 



Cytoplasm. 



Centrosome. 



nuclear membrane. The nuclear substance is composed of 

 a clear fluid called nuclear sap and chromatin, so called 

 because of its staining properties, which is usually in the 

 form of a fine meshwork. There may also be one or more 

 rounded bodies, the nucleoli. Near the nucleus there is 

 a clear rounded body, with radiating processes, called the 



