THE ABDOMEN. 219 



become inserted between the attachments of rbomboideus. 

 and subscapularis, some of the fibres running to the ex- 

 ternal surface of the cartilage of elongation at its posterior 

 part. This, with the corresponding muscle of the opposite 

 side, forms a slingby which the body is anteriorly supported. 



The following are the muscles by which the fore extremity 

 is connected to the trunk : — panniculus carnosus, levator 

 humeri, rhomboideus, trapezius, latissimus dorsi, pectorales 

 magnus, anticus, and transversus, subscapulo-hyoideus, and 

 serratus magnus. 



The f aschia superficialis abdominis must be now removed 

 with care, for on the proper removal of this depends the 

 successful demonstration of the aponeuroses of the abdo- 

 minal muscles. If it has become too dry for removal, it is 

 better to raise it with the tendon of obliquus abdominis 

 externus, the fibres of which run downwards and backwards 

 towards the linea alba. This is a thick elastic band, formed 

 by the general union of the abdominal muscles at the 

 middle line of the abdomen, extending from the ensiform 

 cartilage to the symphysis pubis, before arriving at which 

 it becomes broader and receives fibres from the several 

 tendons of the abdominal muscles, and a distinct band 

 of tendinous fibres from the antero-inferior spinous pro- 

 cess of the ilium, Poupart's ligament or the crural arch. 

 Into this ligament (which is really but a portion of obli- 

 quus abdominis externus), the posterior fibres of the 

 external oblique are inserted, and between these and those 

 inserted into the linea alba is the external abdominal ring", 

 through which passes the spermatic cord, covered by the 

 cremaster muscle. It runs upwards from the external ring 

 posteriorly towards the antero-inferior spinous process of 

 the ilium, the cremaster becoming lost in the lumbar 

 faschia ; the remainder of the cord resting on obliquus 

 abdominis internus, at length passes between its fibres 

 and gains the abdominal cavity at the internal abdo- 

 minal ring, the space between the two rings being the 

 inguinal canal. This is the passage between the external 

 oblique and the internal oblique muscles ; it terminates^ 

 superiorly at the internal abdominal ring, which is formed 

 by the passage of the prolongation of the peritoneum from 

 the floor of the abdomen to line the scrotum, forming the 

 tunica vaginalis scroti; this passes between fibres of the 

 internal oblique muscle. Situated at about the anterion 



