462 



THE MUSCLES AND FASCIA 



spongiosum, by compressing the erectile tissue of the bulb. The anterior fibres, 

 according to Tyrrel, also contribute to the erection of the penis, as they are inserted 

 into, and continuous with, the fascia of the penis, compressing the dorsal vein 

 during the contraction of the muscle. 



The Erector penis (Ischio-cavernous) covers part of the crus penis. It is an 

 elongated muscle, broader in the middle than at either extremity, and situated on 

 either side of the lateral boundary of the peringeum. It arises by tendinous and 



FIG. 298. The muscles attached to the front of the pelvis. (From a preparation in the Museum of the Royal 

 College of Surgeons of England.) 



fleshy fibres from the inner surface of the tuberosity of the ischium, behind the 

 crus penis, from the surface of the crus, and from the adjacent portion of the 

 ramus of the ischium. From these points fleshy fibres succeed, which end in an 

 aponeurosis which is inserted into the sides and under surface of the crus penis. 



Nerve-supply. The perineal branch of the internal pudic. 



Actions. It compresses the crus penis and retards the return of the blood 

 through the veins, and thus serves to maintain the organ erect. 



Between the muscles just examined a triangular space exists, bounded 

 internally by the Accelerator urinae, externally by the Erector penis, and behind 



