14 JOURNAL OF THE 



sist of a very fe'v and delicate fibres. It was not ob- 

 served in any of the several cats dissected by us. 



Transversalis abdominis. The muscle arises along- 

 its dorsal border, just beneath the erectores spinae, 

 from the fascia covering- the ventral surface of the lat- 

 ter (middle la3xr of the lumbar fascia in human anato- 

 my). It also arises from the cartilaofes of the false 

 ribs and from the ventral margin of the ilium. 



Along" its inner border it is anteriorly, and for the 

 g^reater^ part of its course, inserted into a broad, thin 

 aponeurosis which lies dorsal to the rectus abdominis , 

 and is continuous with its fellow of the opposite side 

 as'^an independent aponeurosis. Posteriorly, however, 

 the fibres ^of the muscle pass into a fascia, lying ven- 

 tral to the rectus abdo7mnis, and inseparably united 

 with the combined aponeuroses of the external and in- 

 ternal oblique. 



Synonymy. Latitudinal, S.-D., vol. II, p. 317; trans- 

 versalis, M., p. 142; tTansver sails abdoyyiinis, G. & T., 

 p. 29. 



According to Mivart the muscle ends in an aponeu- 

 rosisHying dorsal to the rectus. Gorham and Tower 

 give the muscle as ending "in an aponeurosis beneath 

 the rectus." Both authors thus overlook the import- 

 ant difference in position between the anterior and pos- 

 terior'portions of the aponeurosis. Strauss-Durckheim 

 evidently recog-nizes this difference, thoug-h he does not 

 explicitly state it. He designates the aponeurosis as 

 the third layer of the abdominal aponeurosis, and goes 

 on to say: "Ce feuillet — s'unit a celui de I'oblique in- 

 terne, et se comporte du reste comme lui." 



Rectus abdominis. The muscle arises from the sym- 

 physis- pubis. It is completely separated by the con- 

 nective tissue of the linea alba from its fellow of the 



