THE CONNECTIVE TISSUES. 



103 



The cellular elements of areolar connective tissue, which, as 

 above stated, are found in the cell -spaces, are either fixed con- 



Fig. 66. Cell - spaces in the ground- 

 substance of areolar connective tissue (sub- 

 cutaneous) of a young rat. Stained in silver 

 nitrate. 



Fig. 67. Three connective-tissue 

 cells from the pia mater of a dog. Stained 

 in methylene-blue (intra vitam). 



nective-tissue cells or wandering or migratory cells. The former 

 are again divided, according to their shape and structure, into 

 true connective-tissue cells or corpuscles, plasma cells, mast-cells, 

 and pigment-cells. 



The connective -tissue cells or corpuscles are flattened, variously 

 shaped cells of irregular form, usually having many branches. The 

 protoplasm is free from granules ; the nucleus, situated in the thicker 

 portion of the cell-body and of oval shape, shows a nuclear net- 

 work and one or several nucleoli. The cells assume the shape of 



Fig. 68. Two pigment cells found on the capsule of a sympathetic ganglion of a frog. 



the space that they occupy and nearly fill. The branches of neigh- 

 boring cells often anastomose through the fine channels uniting the 

 cell-spaces. 



