254 MYOLOGY. 



portions : — The transverse, the iliac, the pelvic, the inguinal, 

 and the perineal. The transverse (fascia transversalis) is inter- 

 posed between the transversalis abdominis and the peritoneum, 

 and is in the horse a very thin structure ; in the human 

 subject, and in some other animals, it is thickened posteriorly, 

 and attached to the crural arch. The iliac fascia (fascia iliaca) 

 covers the muscles of the sublumbar region, especially the psoas 

 magnus and iliacus, which it enfolds and accompanies to their 

 insertion. It is attached internally along the tendon of the psoas 

 parvus muscle, by which it is tensed, externally to the anterior 

 iliac spine ; anteriorly it becomes very rudimentary, although it 

 may sometimes be traced as far as the arcuate ligament of the 

 diaphragm. The sartorius and cremaster muscles arise partly 

 from this fascia. 



The pelvic fascia (fascia pelvica) is a strong layer lining the 

 pelvic cavity, and covered anteriorly by the peritoneum ; inferiorly, 

 it splits into two folds, the external of which lines the sides and 

 floor of the cavity, and is named the obturator fascia, since it 

 covers the internal muscles of that name ; it also furnishes a 

 sheath for the internal pudic vessels. The other fold, the recto- 

 vesical fascia, is reflected inwards and posteriorly gives ofif bands, 

 ene of which separates the bladder from the rectum, another 

 investing the latter, while two others serve as ligaments of the 

 bladder. The inguinal and perineal fasciae will be more appro- 

 priately described in a future section of the work. 



The thoracic fascia stretches across the anterior opening of 

 the thurax, and is its anterior boundary, surrounding and bracing 

 the v.'uious structures which pass through, and helping to keep 

 them in their relative positions. 



FASCIA OF THE ANTERIOR LIMB, 



These correspond to the various regions of the limb. The 

 external scapvlar fascia is very strong superiorly, and it covers 

 the external scapular muscles, giving otf folds which enclose them. 

 It is attached to the cartilage and spine of the scapula, and is 

 continuous with the dorso-lumbar fascia behind, the subscapular 

 fascia round the edge of the antea-spinatus^ and below with the 

 brachial fascia. It is tensed by the pectoralis parvus and teres 

 exteinus muscles. The brachial fascia is comparatively thin ; 

 it covers and invests the humeral and triceps extensor muscles. 



