24 



The Histology and Physiology of the 



Fig. 6. Fig. 7. 



The Knob-like End 



of an arteria 



HELICIN.ffl from a 



Fine Longitudi- 

 nal Section of 

 the Corpus Caver- 

 nosum (Man). Pre- 

 pared in Alcohol, 

 and treated with 

 Carmine. 



The terminal end a 

 appears to lie free in 

 one of the meshes. 

 The mouth of the 

 vessel is seen at *, 

 which appears as a 

 Part of a Fine Longitudinal Section from the Y- sna P e( * fissure. 



Posterior Portion of the Corpus Cavernosum 

 (Man). Prepared in Alcohol, and treated 

 with Carmine. Magnified 160 Diameters. 



In this section the artery a, a, is seen running along the entire length of the 

 section, sending off a number of branches which terminate in thickened ends, 

 c, c, c. The red knob-like ends of this artery are quite conspicuous in consequence 

 of the imbibition of carmine. To the left of the artery is seen the course of a 

 longitudinal muscular bundle, d, which is inserted in the upper third of the artery. 

 Transverse and oblique muscular bundles are seen at e, e. 



claims to have indicated as early as 1857, since which time his 

 statements have become confirmed by the researches of others, who 

 have represented the passage of nerve fibres to the epithelial layers 

 of certain tissues, as for example in the cornea.* He affirms that 

 the epithelial cells of the urethra are in manifold connections with 

 the muscular fibres, nerves, and other tissues of the corpus spon- 

 giosum. " The most superficial cells," he says, " terminate in a 

 pedicle or filiform prolongation, which often remain connected with 

 the mucous membrane after the body of the cell has separated from 

 its connections. A good longitudinal section will often show three 

 or four of such cells, one above the other, hanging like pears by 

 their stalks, the cells directed toward the bladder, the stalk toward 

 the external meatus. To state the precise manner in which these 

 connections occur is reserved for future research. Especially will it 



* Frey, ' Handbuch der Histology und Histochemie,' 3. Aufl., Leipzig, 1870, 

 p. 608. 



