428 



STRUCTURE OF THE TESTICLE. [SECT. 1 96. 



themselves to the borders and surfaces of it, by pointed ex- 

 tremities. 



The glandular substance of the testicle is not homogeneous 

 throughout, but consists of a certain number (100 to 250) of pear- 

 shaped lobules, lobuli testis, which are not completely separated 

 from each other ; these converge by their apices towards the corpus 

 Highmori ; the shortest lobules are those which lie by the side 

 of the septum, and the longest pass between the opposite borders 

 of the organ (fig. 177, n). Each of these lobules is formed by 

 one, two, or three seminal tubules, tubuli s. canaliculi seminiferi, 

 s" t° iV" m thickness, which divide pretty frequently, and per- 

 haps anastomose in their course. Taken together, they thus form 

 a compact mass, in which the separate tubules 

 terminate towards the thick end of the lobule, 

 either in its interior or at its surface, by closed 

 extremities or by loops (fig. 178). The seminal 

 \ tubules of a lobule, although connected with each 

 ) other by some connective tissue and vessels, can 

 still be isolated to a great extent, or even entirely, 

 by careful dissection, and the length of one of 

 them is, according to Lauth, 13 to 33 inches. 

 At the pointed end of each lobule, the seminal tu- 

 bules become more straight, and then pass into the 

 base of the corpus Highmori, either separately or 

 by the union of the 2 to 3 coming from a lobule, 

 to form one tube of ^" in diameter. These have 

 received the name of cluctuli recti, and they form a very dense plexus, 

 the rete testis (rete vasculosum Halleri), 2 to 3 lines broad, and 1^"' 

 thick, extending throughout the entire length of the organ. At the 

 upper end of this plexus, the tubules measure from CC03'" to 008"', 

 and from them arise the excretory seminal tubules, vasa efferentia 

 testis s. Graafiana. These are from 7 to 1 5 in number, and measure 

 cr 1 6'" to o* 1 8"' in diameter. After penetrating the tunica albu- 

 ginea, t\\ey pass on into the epididymis, and here they become 

 attenuated to j£" to y 1 ^'" in diameter, and. again become convoluted 

 in the same way as the seminal tubules within the lobules of the 

 testis. They do not, however, form divisions and anastomoses, 

 but each of the vasa efferentia, in its convoluted course, forms a 

 body, conus vasculosus (s. corpus pyramidale), whose apex is di- 

 rected towards the testicles. These coni vasculosi, connected with 

 each other by connective tissue, compose the head, of the epidi- 

 dymis, and from their tubules, which gradually coalesce with each 

 other at the posterior and upper border of the epididymis, there 



Diagram of the 

 course of a seminal 

 tubule. 



