THE SCROTUM. 1115 
downwards over the cord and encloses its various structures, together with a 
certain amount of areolar tissue derived from the sub-peritoneal tissue of the 
abdominal wall (Figs. 759 and 760). 
Obliquus externus 
Obliquus externus 
Obliquus internus— ybliquus internus (cut) 
Obliquus internus (cut) Transversalis muscle 
Deep circumflex iliac artery : ; 
Over deep epigastric artery 
( Fascia transversalis 
Wi Deep epigastric artery 
Conjoint tendon 
Over outer border of rectus abdominis 
Spermatie cord 
Triangular fascia 
Internal abdominal ring and 
infundibuliform fascia 
Cremaster muscle — 
Obliquus externus — 
Spermatie cord passing ~ 
through cremaster muscle \ 
Fic. 760.—THE Groin. ‘The structures seen on reflexion of part of the obliquus internus (A. M. Paterson). 
In addition to the structures enumerated above, the artery to the vas, the cremasteric artery, 
and the genital branch of the genito-crural nerve, accompany the structures forming the sper- 
matic cord, 
THE SCROTUM. 
The scrotum, in which the testes are placed, varies much in appearance in 
different subjects, and even in the same individual, at different times. As the 
result of cold or of exercise, the wall of the scrotum becomes contracted and firm, 
and the skin covering it wrinkled; at other times the wall may be relaxed and 
flaccid, the scrotum then assuming the appearance of a pendulous bag. The left 
side of the scrotum reaches to a lower level than the right, in correspondence with 
the lower level of the testis on that side of the body. The skin covering the 
scrotum is of a darker colour than the general skin of the body, and is covered by 
hair. The difference in the appearance of the scrotum at different times is due 
to the amount of contraction or relaxation of a layer of muscular fibres placed in 
the superficial fascia. When this muscular layer is contracted, the skin is thrown 
into folds or wrinkles called rugee; when it is relaxed, the skin becomes more 
smooth and even. This muscular tissue is called the dartos muscle. The scrotum 
is marked in the middle line by a median raphe (raphe scroti), which is continued 
backwards towards the anus, and forwards on to the under, or urethral, surface of 
the penis. The interior of the scrotum is divided into two cavities, one for each 
testis, by an incomplete septum (septum scroti), which is in part continuous with 
deeper layers of the dartos tissue. The wall of each of these cavities is formed by 
the corresponding tunica vaginalis, infundibuliform fascia, cremasteric fascia, and 
intercolumnar fascia, while the skin, the superficial fascia, and dartos muscle form 
coverings which are common to the whole scrotum, and enclose both cavities. In 
the superficial fascia of the scrotum there is an entire absence of fat. 
The scrotum in the foetus contains no cavity, but, ike the labia majora in the female, it is 
composed entirely of vascular connective tissue. 
Vessels and Nerves of the Scrotum.—The scrotum receives its vascular supply from the 
superficial perineal branches of the internal pudic arteries which reach its posterior surface, and 
from the external pudic branches of the femoral artery which reach its upper and anterior part. 
The nerves of the scrotum are derived from the superficial perineal branches of the internal 
pudic, from the perineal branch of the small sciatic, and from the ilio-inguinal nerve. The 
