THE MALE GENITAL ORGANS. 



855 



Fig. 398. 



framework, sometimes not very apparent, which, curving upwards at both 

 extremities, extends from that body to the posterior end of the testicle, 

 where it disappears ; from this are given off a large number of fibrillse 

 (trabeculse testis), which diverge in all directions. A mercurial injection 

 by the vas deferens, shows that this part of the testicle is chiefly formed 

 by a ramifying system of rectilinear canals with very thin walls, which 

 open into each other, and unite, on reaching the corpus Highmori, into 

 about twenty principal trunks. These are named the straight canaliculi (vasa 

 recta), to distinguish them from the convoluted tubuli ; they receive the 

 latter at their exit from the lobules, and are surrounded by numerous blood- 

 vessels and sustained by the fibrous septa of the tunica albuginea, which 

 appear to converge towards the point they occupy. At the corpus Highmori, 

 the vasa recta pass through that body, forming in its texture an anasto- 

 mosing network, the rete testis, and are continued into the epididymis as the 

 efferent canals (vasa efferentia). 



The seminiferous tubes in the lobules 

 are from T ^- to the T | 7 of an inch in 

 diameter. They are composed of a 

 very thin fibrous membrane (firmer 

 than that in the walls of similar gland 

 canals elsewhere) ; slightly elastic, 

 and made up of connective tissue 

 with longitudinal nuclei, this mem- 

 brane is lined internally by a proper 

 amorphous membrane (basement) and 

 epithelium. The latter almost com- 

 pletely fills the tubuli ; near the wall 

 of the canal it is composed of polygonal 

 cells, but towards the centre these in- 

 crease in volume, become circular and 

 transparent, and show several nuclei 

 in various stages of transformation ; 

 finally, in the axes of the tubuli can 

 be perceived spermatozoa and the 

 detritus of the spermatic cells. 



Vessels and nerves. The blood is 

 carried to the testicle by the spermatic 

 artery, which is almost exclusively 

 appropriated to it; this vessel, after 

 describing a great number of very 

 remarkable flexions, enters the upper VERTICAL 

 border of the gland, a little behind 

 the epididymis. It does not imme- 

 diately plunge into its substance, how- 

 ever, but passes within the texture of 

 the tunica albuginea, along the borders 

 of the testicle, and forms a complete 

 circle around it. From this circle it 

 sends off divisions, which spread over 

 the sides of the organ, detaching fine 

 arterial ramifications that penetrate its 

 proper tissue in accompanying the interlobular septa. (There is generally 

 described a tunica vasculosa that forms one of the coverings of the testicle. 



SECTION OF THE TESTICLE 

 (HORSE'S), PASSING THROUGH THE CORPUS 



, 



*' 



cord ; 3, Head of the epididymis, or globus 

 major ; 4, Tail of the epididymis, or globus 

 minor ; 5, Vas deferens ; 6, Corpus High- 

 mori ; 1, Rete testis ; 8, Tunica albuginea 

 sending prolongations from its inner face, 

 and which divide the testicle into lobules ; 

 9, Surface of the tunica albuginea. 



