HISTOLOGY. 



vessels and nerves, and of solid branched epithelial cords varying in 

 caliber and frequently anastomosing. Near its border toward the posterior 

 lobe a few of the columns are hollow, and sometimes they contain masses 

 similar to the colloid of the thyreoid gland. This does not come from the 

 granules which occur in varying quantity in all the epithelial cells, giving 

 them sometimes a lighter and sometimes a darker appearance. The 

 granules in some cells are eosinophilic; most of them are not, and a portion 

 may be fat. Ciliated epithelial cells have been recorded. (The part of 

 the anterior lobe which is near the posterior is sometimes called " medullary 

 substance"; in children it may be represented by a cleft-like cavity con- 

 taining colloid). From the relation of the hypophysis to certain diseases, 

 it is quite certain that it produces an important internal secretion. 



Portion of the 

 anterior lobe. 



Epithelial cord. 



Blood vessel con- 

 taining blood 

 corpuscles. 



Portion of the 

 posterior lobe. 



Multipolar cell. 



Connective tissue 

 fibers. 



FIG. 405. PORTION OP A HORIZONTAL SECTION OF A HUMAN HYPOPHYSIS, showing the boundary 

 line between the anterior and the posterior lobes. Two gland follicles on the left each contain a 

 dark epithelial cell. X 220. 



PINEAL BODY. 



The pineal body [epiphysis] is a median dorsal outpocketing of the 

 diencephalon, which has preserved its original epithelial character. It 

 consists of a layer of neuroglia cells thrown into folds and is covered by 

 a connective tissue capsule sending prolongations between the folds. In 

 the pineal body there is found generally "brain sand," acermdus cerebri, 

 which consists of round or mulberry-like concretions 5, to i mm. in diameter. 

 In specimens preserved in glycerin or balsam they show distinct concentric 

 layers. They consist of an organic matrix containing calcium carbonate 

 and magnesium phosphate, and are sometimes surrounded by a thick 

 connective tissue capsule. 



Not infrequently, especially in old age, there are found in the brain sub- 

 stance round or elongated bodies distinctly stratified, which are colored 



