556 



THE TISSUES. 



Fig. 385. 



189J to 481 feet of tubing. Out at the apex of each lobule a single 

 tube, T Jo of an inch in diameter (tubuli recti), passes into the base 

 of the corpus Highmorianum. These form a very close plexus (the 

 rete testis), from the upper end of which proceed 7 to 15 efferent 

 canals (vasa efferentia testis), 6 \ to j z of a line in diameter, which 

 traverse the tunica albuginea, and are continued into the epididy- 

 mis. Here, contracting to J$ to T | n of an inch, they are convoluted 

 in precisely the same way as in the lobules, 

 but without dividing or anastomosing ; and 

 thus form the spermatic cones. These, united by 

 connective tissue, constitute the head (globus 

 major) of the epididymis; at the upper and 

 posterior border of which their canals gradu- 

 ally coalesce, and thus a simple duct is formed, 

 7/5 to g^ of an inch in diameter. (Fig. 385.) 

 This duct is so convoluted as to form the 

 body and tail (globus minor) of the epididy- 

 mis; and, after giving off usually, a cascal 

 prolongation at its inferior extremity (vas 

 aberrans), is ultimately continuous with the 

 vas deferens, already described. 



Structure of the Seminiferous Tubes. 

 The tubuli testis consist of an external 

 fibrous coat, a basement-membrane, and an 



tO ',, 



,A*to 



of an inch in thickness, is tolerably firm 

 and extensible, contains no smooth muscular 

 fibres, and rarely any indications of elastic 

 tissue. The epithelium is simple conoidal, 

 approaching to the scaly variety. In young 

 subjects the cells are pale and finely granular; 

 but as age increases, a continually increasing quantity of fatty 

 granules is collected in them, giving the seminal tubes a light yel- 

 lowish, partially brownish color. The tubes in the rete testis, how- 

 ever, appear to be mere passages in the dense tissue of the corpus 

 Highmorianum, lin-ed by an epithelium. But in the cones the fibrous 

 coat again appears, and to it is added a coat of smooth muscular 

 fibres, continuous upon the vasa deferentia, as before described. 



A view of the minute struc- 

 ture of the testis. 1, 1. Tu- 

 nica albuginea. 2, 2. Corpus 



iiighmorianum. 3,3. Tubuli epithelium, these together being T , 



ZSSZSSttSZ of an inch thick - The flrst avera es 



testis. 6. Vasa efferentia. 7. 

 Coni vasculosi constituting 

 the globus major of the epi- 

 didymis. 8. Body of the 

 epididymis. 9. Its globus 

 minor. 10. Vas deferens. 11. 

 Vasculum aberrans, or blind 

 duct. 



