166 SITUATION OF THE MUSCLES. 



On the lower side of the urethra, near the commencement of 

 the glans penis, there is one or more of them, so large that their 

 orifices sometimes admit the point of a small bougie.* 



These organs when inflamed, secrete the puriform discharge 

 which takes place in gonorrhoea. In a natural state they pro- 

 duce the mucus which is constantly spread over the surface of 

 the urethra, to defend it from the acrimony of the urine, and 

 which passes away with that fluid unperceived. 



The surface of the urethra is endued with great sensibility, 

 and is therefore liable to great irritation from contact with any 

 rough body or any acrid substance. Irritation, thus excited, 

 'induces a state of contraction, which is particularly remarkable, 

 as no muscular fibres are to be seen in its structure. When a 

 bougie has been passed into the urethra for a considerable dis- 

 tance, if it cannot proceed the whole way, it sometimes happens 

 that the instrument will be discharged by a steady uniform 

 motion, which seems to proceed from a progressive contraction 

 of the urethra, beginning very low down. At particular times, 

 after the urethra has been much irritated, it will not receive a 

 bougie, although at other times a bougie of equal size may be 

 passed to the bladder without opposition. This cannot depend 

 upon that elasticity which was noticed before.f 



Upon the two crura of the penis, or the beginning of the 

 corpora cavernosa, are fixed the muscles called Erectores 

 Penis, which are described in the first volume.f These mus- 

 cles cover the crura of the penis from their origin to the junction, 

 and not only compress them, but also influence the motion of 

 the penis when it is distended. 



The bulb of the urethra is covered by a muscular coat, called 

 the Accelerator Urines, which has the effect of driving forwards 



* They were discovered by Plazzoni, of Padua, in 1621. Their number, 

 according to Loder, amounts to about 65. See his plates. H. 



f Sir Everard Home, whose professional opinions are of great weight, has 

 lately described in the Transactions of the Royal Society, the appearance of 

 the lining membrane of the urethra, when viewed through a microscope of 

 great powers. From this paper it seems that he is fully convinced of its 

 muscular structure. H. 



t See description of " Muscles about the Male Organs of Generation," 

 vol. 1, p. 306. 



