MUSCLES OF THE PARIETES OF THE ABDOMEN. 399 



The Iliacus Intern us, 



Occupies the concavity of the ilium, being on the outside of 

 the psoas magnus. It arises, fleshy, from the transverse pro- 

 cess of the last lumbar vertebra; from the internal margin of the 

 crista of the ilium; from the whole concavity of the latter; from 

 its anterior edge at and above the anterior inferior spinous pro- 

 cess; and from that part of the capsule of the hip joint near the 

 latter process. 



This muscle terminates in the tendon of the psoas magnus, 

 just above its insertion into the trochanter minor. 



This and the psoas magnus, from having a common tendon, 

 might with propriety be considered as only one muscle. Their 

 action is the same,* 



Of the Fascia Iliaca. 



The Fascia Iliaca is a tendinous membrane, which lies on the 

 iliacus internus and psoas magnus muscles, and' is continued 

 into the tendon of the Psoas Parvus. Externally, it is connect- 

 ed to the margin of the crista of the ilium; at the internal edge 

 of the psoas magnus, it is connected with the brim of the pel- 

 vis, and sinks into the cavity of the pelvis, being continuous 

 with the Aponeurosis Pelvica; and below, it is inserted into the 

 edge of the crural arch, from the anterior superior spinous pro- 

 cess of the ilium almost to the pubes, and is there continuous 

 with the fascia transversalis abdorninis. The external iliac ves- 

 sels are upon this fascia, between it and tho peritoneum; and 

 below them the fascia iliaca goes over that part of the pubes 

 which gives origin to the pectineus muscle, and is continuous 

 with the pectineal fascia, or that which covers the pectinqus 

 muscle. By introducing the finger or a knife handle into a 

 cut through the fascia iliaca, its attachment to the crural arch, 

 and its continuity with the fascia pectinea will be rendered very 

 obvious. 



* Varieties. Sometimes an additional fasciculus arises below the inferior an- 

 terior spinous process, and descends along the external margin of this muscle. 

 This fasciculus varies somewhat in its size at different points, and is inserted into 

 the linea aspera below the trochanter minor. In very rare cases, the iliacus in- 

 ternus is kept totally distinct from the psoas magnus, from origin to insertion. 



