MUSCULAR SYSTEM. 123 



the lumbar vertebrae : joosteriorly, to the small internal trochanter 

 of the OS femoris. 



Relations. — Anteriorly and externally, with the diaphragm ; 

 posteriorly and externally, with the iliaciis ; inferiorly, with the 

 kidney and peritoneum ; on the inner side, with the psoas niag- 

 nus and lumbar vertebrse; behind, with the quadratus lumborum. 



Structure. — Anterior attachments, fleshy. The posterior end 

 is included within an aponeurosis, which itself terminates in a 

 flat tendon, into which are concentrated and inserted the fibres of 

 the iliacus. 



Action. — To bend the haunch upon the pelvis, by drawing it 

 forward, as in progression. Supposing it to act while the hind 

 quarters remain stationary and fixed points, it will produce that 

 appearance, by flexing the spine, called " roach-back," or 

 " sticking up the back." 



ILIACUS. — lleo-trochantineus. 



Situation. — Occupying the iliac fossa, and thence extended 

 along the internal part of the haunch. 



Form. — Thick; triangular; base turned forwards. 



Attachment. — Anteriorly and superiorly, to that part of the 

 crista of the ileum which has no bearing upon the sacrum; and 

 to the anterior spinous process, venter, and inferior edge of the 

 bone : posteriorly and inferiorly, to the small internal trochanter, 

 along with the psoas magnus. 



Relations. — 'Inferiorly, with the crural arch ; superiorly, with 

 the psoas magnus and sartorius; on the outer side, with the iliac 

 fossa, tensor vaginae, rectus, and ileo-femoral articulation ; on the 

 inner, with the iliac faschia and peritoneum. The anterior crural 

 nerve and profunda artery and vein cross its lower termination. 



Structure. — Enveloped entirely internally, and in part exter- 

 nally, by a faschia derived from the crural arch. It is altogether 

 fleshy excepting its lower part, which joins in inseparable union 

 with the tendon of the psoas magnus. 



Action. — To flex or advance the haunch. 



PSOAS PARVUS. — Suh-lumbo-pubialis. 



Situation. — Along the inner side of the preceding muscle. 



Figure. — Elongated, slender, fusiform. 



Attachment. — Anteriorly, to the heads of the 16th, 17th, and 

 18th ribs ; to the bodies of the three posterior dorsal, and to those 

 of all the lumbar vertebrae ; posteriorly, to the brim of the pel/is, 

 midway between the anterior spine and the symphysis pubis. 



Relations. — Anteriorly, with the diaphragm and the renal 

 vessels ; on the inner side, with the crus of the diaphragm, ante- 



