ASEPTIC CASTRATION OF MALE ANIMALS. 
251 
which is derived from the external oblique muscle. This is 
attached around the external abdominal ring and passes down 
over the cord and testicle. Inside this, is the cremasteric fascia, 
which is an expansion of the cremaster muscle. This arises 
from the iliac fascia and passes down the inguinal canal and 
spermatic cord to surround the testicle. This fascia forms only 
an incomplete covering, while still deeper is the infundibuli- 
form fascia, which is an extension from the transversalis abdo- 
minalis muscle fascia. This is funnel-shaped and commences 
at the internal ring, passing down over the cord and testicle, and 
on the inside is continuous with the outer serous covering of 
the testicle. 
Then we have the two peritoneal coverings, which are 
brought down by the testicle when it passes from the abdominal 
cavity to the scrotum. The outer one is spoken of as the 
tunica vaginalis refiexa, and is united by cellular tissue to the 
infundibuliform fascia, on its outer surface. 
The inner serous tunic, known as the tunica vaginalis prc- 
pria, is attached on its inner side to the outer fibrous coat of the 
testicle; and the surface of these peritoneal coverings, which 
are in contact with each other, are lined with a single layer of 
squamous epithelium (endothelium) and thus forms a large 
lymph space, which is continuous with the peritoneal cavity, 
being, in fact, a portion of it, which was carried down with the 
testicle when it passed into the scrotum. 
The testicle is the essential reproductive gland of the male. 
It is composed of an outer fibrous covering, from which trabe¬ 
culae extend inwards, dividing the gland up into pyramidal 
shaped spaces that contain the active secreting gland substance. 
It is surmounted on the superior border by the epididymis, 
which is the first portion of the excretory canal and which ter¬ 
minates in the vas deferens. 
The testicle is suspended in the scrotum by the spermatic 
cord, which is composed of the vas deferens, posteriorly, and on 
the anterior border we have the great testicular or spermatic 
artery, which is very tortuous; and between these, we have a 
