198 ANATOMY OF THE RABBIT. 
(g) The spermatic vein (v. spermatica) is formed by a network 
of vessels, the plexus pampiniformis, which surrounds the 
internal spermatic artery in its posterior portion. It opens 
forwards into the inferior caval at the angle formed by the 
latter with the renal artery. (That of the right side enters 
the inferior caval at about the level of the spermatic arteries.) 
Owing to the open communication of the testis sac with the abdom- 
inal cavity, the association of the ductus deferens with the spermatic 
vessels to form a spermatic cord (funiculus spermaticus) is very 
imperfectly expressed. 
2. The connections of the deferent ducts with the common 
urinogenital tube and related parts may be displayed by dividing 
the symphysis and dissecting in the interior of the pelvis. The 
structure and attachments of the penis should first be examined. 
Apart from its terminal portion, the glans penis, and the 
urethra, the body of the penis is chiefly formed by a pair of hollow 
fibrous structures, the cavernous bodies (corpora cavernosa penis). 
Eack of these is firmly attached to the posterior margin of the 
ischium by a white fibrous cord, the crus penis. The latter is 
partly concealed by a short thick ischiocavernosus muscle, 
the origin of which occupies a similar position on the ischium. 
The penis is also attached to the symphysis by a short but stout 
suspensory ligament (lig. suspensorium) and by a thick spindle- 
shaped pubocavernosus muscle lying between the ischiocaver- 
nosi. 
The attachments of the penis should be severed at the posterior 
border of the ischium and the symphysis divided. By pressing 
apart the two sides of the pelvis the urinogenital tubes, with the 
penis and the pelvic portion of the rectum, may be dissected out 
and removed from the body. 
The middle haemorrhoidal artery (a. haemorrhoidalis media), a branch 
of the hypogastric, passes to the side of the rectum, to the urethra, and to the 
seminal vesicle. The internal pudendal artery (a. pudenda interna), accom- 
panied by the corresponding nerve and vein, passes to the side of the penis, giving 
off the inferior haemorrhoidal artery to the terminal portion of the rectum 
and to the associated rectal or anal gland. The rectum is connected with the 
root of the tail by the rectocaudalis muscle, a somewhat spindle-shaped 
aggregation of smooth muscle fibres, arising from the body of the second caudal 
vertebra, and inserted a short distance forwards on the dorsal surface of the 
