146 PRACTICAL HISTOLOGY [XVIII 



The trabeculge, which divide the outer portion of 

 the gland, the cortex, into compartments, the alveoli, 

 and which then in the inner portion, the medulla, 

 of the gland split up into bands, forming a network 

 with rather narrow, elongated meshes. 



In the alveoli of the cortex the roundish masses of 

 tissue crowded with leucocytes, the follicles of the 

 cortex; in the intertrabecular spaces of the medulla 

 the elongated masses of similar tissue, the medullary 

 cords. Note that the follicles are continuous with the 

 medullary cords. 



Around the follicles and around the medullary 

 cords and separating them from the trabeculse the 

 lymph-channels comparatively free from leucocytes. 



Some of the follicles will probably show a central 

 round area, the germinal area, resembling somewhat 

 in appearance the Malpighian corpuscles of the spleen 

 (cp. Less. xix.). 



b. Observe under a high power 



The connective-tissue of the capsule and trabeculse 1 

 continuous with 



The reticulum of the lymph- channels. 



Limiting the follicles and medullary cords may 

 usually be seen a fine line with nuclei at intervals, 

 indicating the flat cells bounding the lymph-channel. 



The adenoid tissue of the follicles and cords, con- 

 tinuous with that of the lymph-channels but with finer 

 fibres and smaller meshes ; unless the section has been 

 well shaken this will be largely hidden by leucocytes. 



1 In some animals, e.g. ox, this contains unstriped muscular 

 fibres. 



