GLANDS. 121 



kidney but somewhat more dense. Its external 

 surface, excluding that portion corresponding to the 

 hilus of the organ, is clothed with a simple layer of 

 the epithelium, which constitutes the visceral ]amina 

 of the serous membrane of the testis (tunica vagina- structure. 

 li$) ; its internal surface is in immediate relation with 

 the secreting tubules of the gland. Along the line 

 where its vessels enter and leave the organ (hilus)* 

 the tunica alkuginea presents a very considerable 

 thickening (corpus HigJimorianutri), which, in the 

 form of a ridge, buries itself in the parenchyma of 

 the gland, and from its surface the interlobular 

 fibrous septa take their origin. In the interior of the 

 corpus Highmorianum is a tubular network (rete tes~ 

 tis), from which the secreting tubules are given off on 

 one side, and from the other, the efferent canals which 

 terminate in the excretory duct. 



From the interior of the rete testis twenty to thirty vasa recta, 

 straight tubes, rVth of a line in their mean diameter, 

 take their origin (vasa recta), and, after a short 

 course, divide into several branches. Each one of 

 them becomes exceedingly tortuous (PI. XXL fig. I), 

 and again gives off several subdivisions, which anasto- 

 mose with each other, and terminate either by loops, 

 or by blind extremities. Sometimes one of these 

 branches, but more frequently two or three of them 

 closely united, form a lobule of a conical shape, the 

 apex of which is in relation with the rasa recta, whilst 

 its base looks towards the periphery of the organ. 

 Not unfrequently canals of communication exist be- 

 tween these lobules. 



The upper extremity of the rete: testis gives off a E fferen t tubes. 



8 



