THE PENIS. 



1967 



somewhat expanded crura attached to the inner border of the pubic arch, the cavern- 

 ous bodies are at first separated by an interval occupied by the bulb of the corpus 



Fig. 1674. 





D 



ddv sdv sk da 



E 



da ddv sdv 



Cross-sections of formalin-hardened penis at different levels. ^, through glans, near tip; 5, abont 

 middle of glans; C", through corona; D, body, distal part; E, body, proximal part, cc, corpus caver- 

 nosum ; cs, corpus spongiosum ; da, dorsal artery ; ddv, deep dorsal vein ; e, fibrous envelope ; eg, erectile 

 tissue of glans ; f, frenum ; ft, fibrous tissue ; s, fibrous septum ; sdv, superficial dorsal vein ; sf, super- 

 ficial fascia ; sk, skin ; ia, tunica albuginea ; u, urethra. 



spongiosum. Farther forward, in the vicinity of the penile angle, the corpora caver- 

 nosa press against each other with their median surfaces, the opposed flattened cap- 

 sules blending to form a median partition (septum penis). Lower the latter becomes 

 imperfect and replaced by a series of vertical bands, and hence is often designated the 

 pedinifortn septum,, the intervening 



slit-like apertures permitting commu- 

 nication between the blood-spaces of 

 the two cavernous bodies, as well as 

 the passage of anastomotic branches 

 of their arteries. In certain mammals, 

 especially the carnivora and some 

 marsvipials, a bone (os penis) is de- 

 veloped within the fibrous septum. 

 On approaching the corona, the cor- 

 pora cavernosa again become discrete 

 and rapidly taper to blunt-pointed 

 ends that are separated externally by a 

 slight furrow and capped by the over- 

 lying glans. The dorsal and under 

 surfaces common to the closely ap- 

 plied cavernous bodies are marked by 

 longitudinal grooves ; that along the 

 former surface lodges the dorsal ves- 

 sels of the penis, while the under fur- 

 row is filled by the spongy body. 



The corpus spongiosum (cor- 

 pus cavernosum urethrae), the third and 

 much smaller, although longer (about 



Fig. 1675. 



Dorsal vein 

 now double 



Pubic bo 



Crus 



Deep artery in 



corpus cavernosum 



Urethra' 



Ischio-cavernosus- 

 muscle 



Bulb 



Bulbo-cavernosus' 

 muscle 

 Colles's fasc 



^ '' A, (" ~ 



Frontal section through pubic arch and root of penis. 



17 cm. or 6^ in.), cylinder of erectile tissue, occupies the groove along the under 

 surface of the cavernous bodies. The two ends of this cylinder are enlarged, the 



