134 ON THE ANATOMY OF COGIA BEEYICEPS. [May 21, 



Figures 15-25 refer to the Penis. 



Fig. 15. View of the entire penis from the right side (i nat. size): the penial 

 sheath is opened to show the tip of the glans. A portion of the abdo- 

 minal wall (B) is represented to show the connection of the muscles of 

 the sheath. 



16. Transverse section of the body of the penis (nat. size). 



17. Transverse section of penis about (5 inches from the tip (nat. size). 



18. Transverse section of penis two inches below the tip (nat. size). 



19. A dissection of the base of the penis (i nat. size) : the upper half of 

 the muscles and of the corp. cavernosuin and corp. spongiosum has 

 been sliced away so as to expose the crura of these two bodies. 



Plate XI. 



Fig. 20. Transverse section of the base of the penis at the point of bifurcation 

 of the erectile tissues (£ nat. size, somewhat diagrammatic). It 

 exhibits the relation of the muscles to the crura. 1, 2, connective- 

 tissue septa. 



21. A sperm-duct opened, a, its upper region ; b, its lower region. 



22. Internal surface of the hind wall of the bulbus urethra: and the 

 commencement of the penial region of the urethra, a, the mouth of 

 shallow pit, which is drawn on an enlarged scale at the side to show 

 the apertures of the two sperm-ducts. 



23. Ventral view of the base of the penis (% nat. size). 



24. Dorsal view of the base of the penis (J nat. size), with the pelvic fascia 

 in situ, and a couple of lymphatic glands on the left. In the centre, 

 forwards, the origin of the compressor urethra? (Cm.) in the under sur- 

 face of the fascia is indicated. 



25# Dorsal view of the base of the penis after removal of the pelvic fascia 

 (2 nat. size). The "sphincter ani"has been turned backwards to 

 show the compressor urethric and termination of the retractor penis 

 in the rectal muscles. 



Explanation of the lettering. 



Ac, accelerator urinaj muscle. Ac.', its posterior division. a>\, pudic 

 artery. Bv., blood-vessels on penis. Ca., corpus cavernosum. 

 Cr.ca,, crus. corp. cavernosi. Gr.ap., crus corp. spongiosi. cm., cir- 

 cular muscles in sheath of penis. Ct., connective-tissue coat of penis. 

 C.u., compressor urethra? muscle, ep., epidermis of glans penis. 

 Er., erector penis muscle, g, lymphatic gland. <//./>., glans penis. 

 I., pelvic ligament, lev., levator am muscle, m., muscle of doubtful 

 homology. P., external aperture of penial sheath. Pro., prostate 

 gland or its pores. R., rectum. Be., retractor penis muscle, r, longi- 

 tudinal ridges in sperm-duct. S.d., sperm-duct, or its opening into 

 urethra. <SA.,shodth of penis. Sp., corpus spongiosum. Sph., sphincter 

 am muscle, t., tendinous patch on erector muscle, tu., tunic of corp. 

 cavernosum. U., urethra, v., valves in sperm-duct. 



