ADRENAL (SUPRARENAL GLAND). 



149 



rated by blood capillaries. The cells possess a granular proto- 

 plasm which often contains fat droplets. The nuclei are placed 

 centrally, and are vesicular in character. 



3. The zona reticularis is composed of cells somewhat simi- 

 lar to those of the zona fasciculata. They are arranged in 

 columns which form a distinct network, as shown in Figs. 105 

 and 107. They occupy the meshes of a fine capillary plexus. 



FIG. 107. 



Longitudinal section of the adrenal of an adult dog. X 150. Hardened in corrosive 

 acetic mixture and stained with iron haernatoxylin and erythrosin. (Flint.) 



The medulla consists of polygonal cells with lightly 

 staining protoplasm and deeply-staining nuclei. They are 

 grouped together into round or oval masses, which are sur- 

 rounded by numerous blood-vessels and separated by septa of 

 reticulum. The cells often surround a blood-vessel like the 

 epithelial cells of a gland duct. 



