OF THE ABDOMEN. 



363 



lined by the fascia transversalis, which separates it from the peritoneum. Its 

 lower border forms the upper boundary of the spermatic canal. 



Fig. 232. The Transversalis, Bectus, and Pyramidalis Muscles. 



I, in eat alia 



Lumbar Fascia (Fig. 238). The vertebral aponeurosis of the Transversals 

 divides into three layers ; an anterior, very thin, which is attached to the front 

 part of the apices of the transverse processes of the lumbar vertebrae, and, 

 above, to the lower margin of the last rib, where it forms the ligamentum 

 arcuatum externum; a middle layer, much stronger, which is attached to the 

 apices of the transverse processes ; and a posterior layer, attached to the apices 

 of the spinous processes. Between the anterior and middle layers is situated 

 the Quadratus Lumborum ; between the middle and posterior, the Erector 

 Spina3. The posterior lamella of this aponeurosis receives the attachment of 

 the Internal Oblique; it is also blended with the aponeurosis of the Serratus 

 Posticus Inferior and with that of the Latissimus Dorsi, forming the lumbar 

 fascia. 



