166 ANATOMY OF THE ABDOMEN, ETC. 



the inner lip of the crest of the ilium, from the lumbar 

 fascia, i. e., from the spiiioiis processes and the tips and 

 bases of the transverse processes of the lumbar vertebras, 

 and from the under surface of the last six or seven ribs, 

 where it indigitates with the diaphragm. Its fibres pass 

 transversely forward, and terminate in an aponeurosis, the 

 upper two-thirds of which passes behind, and the lower 

 third in front of the rectus muscle, to be inserted into the 

 linea alba. The lower fibres of the muscle cover over the 

 spermatic cord, or round ligament, and are inserted into 

 the pectineal line, in connection with the lower fibres of the 

 internal oblique, under the name of the conjoined tendon ; 

 these lower fibres are few in number, and separated from 

 each other ; indeed, the portion arising from Poupart's 

 ligament is sometimes deficient, and at others confounded 

 with, and inseparable from, the internal oblique ; in either 

 case the transversalis fascia and peritoneum maybe seen 

 through the fibres : the internal oblique usually descends 

 nearest to Poupart's ligament, while the transversalis 

 makes up the greater part of the conjoined tendon. The 

 circumflexa ilii artery, a branch of the external iliac, and 

 the musculo-cutaneous nerve from the lumbar plexus, 

 ramify upon and in this muscle above the crest of the ilium. 



The rectus muscle is exposed by dividing the aponeurosis which 

 covers it in front, from the sternum to the pubes, at about an inch 

 from the median line ; at two or three points this sheath will be 

 found adherent to certain tendinous intersections which traverse the 

 muscle ; the aponeurosis should be carefully dissected from them. 



The RECTUS MUSCLE, broad above and narrow below, 

 arises by a thick tendon from the crest of the os pubis ; 

 becoming thinner as it grows broader, it is inserted into 

 the cartilages of the fifth, sixth, and seventh ribs ; it is 

 separated from its fellow by an interval, formed by the 

 aggregation of the fibres of the tendons of the abdominal 

 muscles of the two sides, which constitutes the linea alba. 

 Two or three tendinous intersections, sometimes complete, 

 at others only partial, cross the rectus in irregular direc- 

 tions ; they are called linese transversae, and serve to keep 

 the muscle flat during its contractions, since without them, 

 its broad insertion and narrow origin would give it a tend- 

 ency to roll into a cone longitudinally. The rectus mus- 

 cle is occasionally inserted as high as the fourth, or even 

 third rib. Sometimes there may be found an abnormal 



