STRUCTURE OF THE CORPORA CAVERXOSA. 



957 



tissue of the two sides. From the direction of these slits, the intermediate 

 white portions of the septum are made to resemble in arrangement the teeth 

 of a comb, and hence it is named *eptum pectiniforme. 



The external fibrous investment of the cavernous structure is white and 

 dense, from half a line to a line thick, and very strong and elastic. It is 

 composed for the most part of longitudinal bundles of shining white fibres, 

 with numerous well-developed elastic fibres, enclosing the two corpora 

 caverriosa in a common covering ; but internal to this, in each compartment, 

 is a layer of circular fibres, which enter into the formation of the septum. 

 (J. Wilson and Ellis.) 



From the interior of the fibrous envelope, and from the sides of the 

 septum, numerous lamellse, bands, and cords, composed of au extensible 

 fibrous tissue, and named trabeculce, pass inwards, and run through and 

 across the cavity in all directions, thus sub- 

 dividing it into a multitude of interstices, and Fig. 671. 

 giving the entire structure a spongy character. 



Fig. 671. TRANSVERSE SECTION OP THE PENIS IN THE 



DISTENDED STATE. 



The integument is represented as surrounding the 

 deeper parts ; the erectile tissue occupying the corpora 

 cavernosa and the septum pectiniforme descending be- 

 tween these bodies ; u, placed on the section of the 

 spongy hody, marks the urethra in the form of a trans- 

 verse slit ; v, the single dorsal vein ; a, the dorsal 

 arteiy, and n, the nerve, of one side. 



The trabeculae, whether lamelliform or cord-like, are larger and stronger 

 near the circumference than along the centre of each cavernous body, and 



Fig. 672. PORTION OP THE Fig. 672. 



ERECTILE TISSUE OF THE 

 CORPUS CAVKRNOSUM MAG- 

 NIFIED, SHOWING THE AREO- 



LAR STRUCTURE AND THE 

 VASCULAR DISTRIBUTION 

 (from J. Mullet). 



a, a small artery supported 

 by the larger trabeculae, and 

 branching out on all sides ; c, 

 the tendril-like arterial tufts 

 or helicine arteries of Miiller ; 

 d, the areolar structure formed 

 by the finer trabeculae. 



they also become gradually 



thicker towards the crura. 



The interspaces, conversely, 



are larger in the middle 



than near the surface ; 



their long diameter is, in 



the latter situation, placed 



transversely to that of the 



penis ; and they become 



larger towards the forepart of the penis. They are lined by a layer of 



squamous epithelium. The trabeculse contain the ordinary white fibrous 



tissue and fine elastic fibres, together with pale muscular fibres, arteries, and 



