1106 UROGENITAL SYSTEM. 
number of slender tubes which run a straight course. These latter are called 
tubuli recti, and open into the complicated canal network of the mediastinum, which 
has received the name rete testis. 
Microscopic sections show that the walls of the seminiferous tubules are composed of 
a firm basement membrane and of an epithelial lining, formed of several layers of cells. 
Certain cells of this epithelium are constantly undergoing transformation into spermatozoa, 
and the appearance of a tubule in section varies much, according to the greater or less 
activity of its epithelial cells. 
The secretion of the seminiferous tubules is carried through the tubuli recti 
into the rete testis, and leaves the latter, to reach the canal of the epididymis, 
through from fifteen to twenty minute tubules called vasa efferentia (ductuli 
efferentes testis). These latter tubules pierce the tunica albuginea and enter the 
globus major, which is in direct contact with the upper end of the testis. Kach 
vas efferens is at first straight, but soon becomes much convoluted, and forms a little 
conical mass called a conus vasculosus. Within the globus major the little twisted 
eanals finally open into the single much convoluted tube which constitutes the 
BIG. 752: 
A. The right testis and epididymis, seen within the tunica vaginalis, which has been opened up. 
B. The right testis and epididymis seen from behind, after complete removal of the parietal portion of the 
tunica vaginalis. 
C. Diagram to illustrate the structure of the testis and epididymis. 
c.v. Coni vasculosi. r.v. Rete testis. t.v. Tunica vaginalis. 
e.  Epididymis. s. Septula testis. t.v’. Cut edge of tunica vaginalis. 
g.m. Globus major. s.c. Spermatic cord. v.d. Vas deferens. 
g.m'. Globus minor. s.t. Seminiferous tubule. v.e. Vas efferens. 
h.  MHydatids. t. Testis. v.r. Tubuli recti. 
chief bulk’ of the epididymis, and is called the canal of the epididymis (ductus 
epididymidis). This canal, which is not less than 19 or 20 feet in length, may be 
said to begin in the globus major, and to end, after an extraordinarily tortuous 
course, at the globus minor by becoming the vas deferens (ductus deferens, Fig. 752). 
In most cases one or more slender convoluted diverticula from the canal of the 
epididymis may be found near its lower end. ‘These receive the name of vasa aberrantia 
(ductuli aberrantes), and one of them which is very constantly present often measures a 
foot or more in length. 
Minute Structure.—The canal of the epididymis and the vasa efferentia are lined 
by a ciliated epithelium, the cilia of which maintain a constant current towards the vas 
deferens. The canal of the epididymis possesses a muscular coat composed of an inner 
stratum of transversely and an outer stratum of longitudinally directed fibres. The wall, 
at first thin, becomes much thicker as the canal approaches the vas deferens. 
Vessels and Nerves of the Testis.—The testis is supplied by the spermatic artery, a branch 
of the aorta. This slender vessel, after a long course, reaches the posterior border of the testis, 
res t.5 
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