MALE OKGANS OF REPRODUCTION 



499 



any such, the lumen of others being subdivided by deep rugae into 

 numerous anastomosing compartments. The amount of the folding also 

 varies in different species, being more highly developed in some of 

 the lower mammals, e.g., the dog, than in man. 



The lumen of the prostatic tubules is broad, and is beset with numer- 

 ous alveolar dilatations and shallow diverticula. It is usually broader 



FIG. 442. PORTION OF PROSTATE GLAND OF AN OLD MAN, SHOWING THE PROSTATIC 

 CONCRETIONS. 



In the upper right hand concretion the concentric lamellae are clearly discernible. 



near the blind extremity and diminishes somewhat in diameter toward 

 the duct. The caliber of the lumen also varies greatly in different 

 tubules and is possibly dependent in part upon the state of secretory 

 activity. The contents of the lumen include the granular albuminous 

 secretion, desquamated epithelial cells, and, as age advances, many so- 

 called prostatic concretions ('corpora amylacea'; 'prostatic calculi'). 

 The concretions vary greatly in size (10 /*. to 1 mm. in diameter), 

 and may be homogeneous, but more frequently present a distinctly 



