156 ANATOMY OF THE WOOD RAT 



ments are aponeurotic and exceedingly thin, so that a num- 

 ber may occupy a very narrow space. In making them suffi- 

 ciently wide in the illustrations for proper definition, distor- 

 tion in respect to their precise locations upon the bones has 

 been inevitable. 



The cranio-lateral process of the ilium is termed the spine, 

 and from it originates Poupart's ligament. The cranio- 

 medial face of this may project farther craniad than the spine 

 itself, and from this portion originates part of the longis- 

 simus dorsi. As previously mentioned, there is much individ- 

 ual variation at this point. From the spine extend two 

 borders and a ridge. The superior border exhibits variation, 

 chiefly due to the fact that a good portion of it articulates, 

 upon its medial surface, with the sacrum ; but from its caudal 

 portion originates the gemellus superior. At a point about 

 three-fifths caudad along the superior border is the posterior 

 superior spine, marking the caudal termination of the articu- 

 lation with the sacrum. Just caudad of this is situated 

 the gluteal notch, over which passes the superior gluteal 

 nerve. Upon the lateral ridge there is no muscle attached, but 

 between this and the superior border lies the superior gluteal 

 fossa, giving origin to the gluteus medius, and between it 

 and the inferior border is the inferior gluteal fossa, from 

 which originates the gluteus minimus. Adjoining the latter 

 upon the cranial portion of the inferior border is the origin of 

 the gluteus superficialis anterior, and mediad, that of the 

 iliacus, which follows the well-defined iliacal ridge almost 

 to the femoral process. There is great variation in all of 

 these details, but this seems to be purely individual. Im- 

 mediately craniad of the acetabulum is the femoral process, 

 from which originates the rectus femoris. 



Upon the medial side of the ilium is located the extensive 

 and variable articular surface, by which the innominate is 

 joined to the sacrum. Upon the cranio-Ventral border is 

 usually, though not always, a small process upon which is 



