1252 



URETHRA. 



we shall deny any muscular membrane to this 

 region of the urethra : but it seems more na- 

 tural to regard the whole corpus cavernosum 

 as a highly developed muscular layer provided 

 with peculiar bloodvessels ; for a large quan- 

 tity of smooth muscular fibres, together with 

 the cellular tissue, vessels, and nerves, en- 

 tering into the structure of its beams and 

 cords as far as the glans, render this body an 

 eminently contractile structure."* 



On laying open the urethra from its origin 

 at the neck of the badder, the first structure 

 we meet with is the caput gaUinaginis (colli- 

 culus seminalis, caruncula seminalis, veru mon- 

 tanum, crista uretlirce). This is an elongated 

 body situated on the floor of the pro.-,tatic 

 part of the urethra : it varies in length from 

 three quarters of an inch to an inch. Com- 

 mencing by a gentle elevation of the urethra, 

 towards which, on either side, are seen some 

 delicate folds of membrane passing, it expands 

 into a small oblong rounded eminence, com- 

 pared to the head of a woodcock, and hence 

 its name : it then advances gradually, tapering 

 to a slender point, which, being continued 

 onwards for some distance, is lost at the 

 beginning of the membranous portion in one 

 or two delicate longitudinal folds, and is con- 

 founded with the general surface of the 

 urethra : the latter part is compared to the 

 beak of the bird. The caput gaUinaginis di- 

 vides the prostatic sinus into two lateral de- 

 pressions, into which the secretion of the 

 prostate gland is poured. 



At the most elevated portion of the caput 

 gaUinaginis there is a depression formed by an 

 inflexion of mucous membrane, facing for- 

 wards, variable in size and depth, and gene- 

 rally capable of admitting the blunt end of 

 an ordinary probe : in some cases it can be 

 traced down beneath the third lobe of the 

 prostate, to the extent of the third, or even 

 the half, of an inch. It is called the sinus pocu- 

 laris, utriculus prostaticus, or vesica prostatica, 

 and is the homologue of the protometra, from 

 which the female uterus is evolved.^ On 

 either side of this, between its laminae, or 

 beneath it, are the terminations of the ejacu- 

 latory ducts. A general description of this 

 small cavity has been given under the head of 

 PROSTATE GLAND. 



The structure of the caput gaUinaginis is 

 this : it is for the most part formed of a 

 raised fold of the ordinary mucous membrane 

 of the urethra, beneath which is a longitudinal 

 layer of elastic tissue continuous with the 

 trigone. Some anatomists also affirm that 

 there is mixed up in the tissue of the body 

 a plexus of vessels, constituting a distinct 

 erectile tissue ; and hence it has been ima- 

 gined, that when its vessels are distended with 

 blood, as during erection of the penis, it shuts 

 up the prostatic portion of the urethra, and 

 thus prevents the passage of the semen in a 

 retrograde direction into the bladder. My 



* Kblliker, Beitrage zur Kenntniss der glatten 

 Muskeln, in the Zeitschrift fur Wissen. 

 t See article PKOSTATE. 



own opinion as to its use is, that, independent 

 of this office, it is endowed with special sensi- 

 bility, like the papillary orifices of the ducts 

 of Steno and Wharton ; and that it is capable, 

 under the influence of a stimulus, of becom- 

 ing erect, and thus straightening the termina- 

 tion of the canals connected with it, by which 

 the exit of the secretion of the testes and 

 vesiculae seminales is favoured. I believe, 

 further, that something more is due to these 

 papillary orifices of the ducts of glands, and 

 that, in consequence of their exquisite sensi- 

 bility and sympathy with the glands, they 

 possess a power, under stimulation, of elicit- 

 ing the secretion and expulsion of the fluid of 

 the bodies with which they are connected. A 

 proof of its sensibility may be deduced from 

 the fact, that when a bougie, introduced for 

 the first time per urethram, reaches this point 

 of the canal, it frequently gives rise to faint- 

 ness and sickness ; and this is usually attended 

 with an almost irresistible desire to micturate ; 

 and further, that if this be frequently re- 

 peated, and the caput gaUinaginis be irritated, 

 a flow of semen and vesicular secretion can 

 be excited. 



The pathology of this portion of the canal 

 leads to the same conclusion. For the relief 

 of nocturnal emissions, so frequently the result 

 of repeated self-pollution, the preternatural 

 irritability of this part may be successfully 

 destroyed by the application of the nitrate of 

 silver. 



If the caput gaUinaginis be gently raised by 

 dissection from the subjacent tissue, it will be 

 found lying on a delicate tendinous layer, with 

 which it is intimately connected. This layer in 

 shape resembles the body itself, being broader 

 behind and tapering in front, and is gradually 

 confounded with the tendinous covering of 

 the spongy body : it is also continuous with 

 the fascial layer of the utriculus prostaticus. 



The caput gaUinaginis results in a great 

 measure from the coalition of the two lateral 

 portions of the urethra, during the develop- 

 ment of the back part of the canal, from that 

 portion of the uro-genital sinus which gives 

 origin to the prostate and vesiculte semi- 

 nales, &c. 



In the membranous portion there is nothing 

 specially remarkable, except that delicate 

 venous plexus, to which allusion has been 

 already made. In the bulbous part are the 

 terminations of the ducts of Cowper's glands ; 

 and to these bodies I shall now direct attention. 



COWPER'S GLANDS (glanduIcE Cow-peri, 

 gladnulce antiproslaticee vel prostaticce inferiores) 

 are two glands situated beneath the anterior 

 portion of the membranous part of the urethra, 

 just behind the bulb, between the layers of 

 the triangular ligament. A few fibres of the 

 compressor urethras pass beneath them. Some- 

 times a single gland only is found, and occa- 

 sionally there are three ; in which case, ac- 

 cording to Cowper, the additional gland is 

 placed just beneath the pubis. These bodies 

 are frequently difficult to find, and in old 

 persons they either disappear altogether, or 

 become so soft that it is impossible to recog- 



