VESICULffi SEMINALES. 155 



vasa deferentia into the vesiculae seminales, than it does from 

 these last mentioned organs into the duct. 



The union formed by the short duct of the seminal vesicle 

 and the vas deferens of each side constitutes the ductus ejacula- 

 torius, which is about an inch in length, and runs in close con- 

 tact and parallel with its fellow of the opposite side, between 

 the middle and lateral lobes of the prostate, and opens 

 obliquely into the urethra by a small oblong orifice in the 

 caput gallinaginis. Each ejaculatory duct is a conoidal tube, 

 its apex being at its orifice in the urethra. Hence fluids pass 

 so readily into the seminal vesicles, when injected along the 

 vasa deferentia. The diminution of the duct at its urethral 

 orifice, will also increase the force of the jet, by which the fluid 

 of the vesicle is ejected, when spasmodically compressed by 

 the levator ani muscle. — , 



These organs were generally regarded as reservoirs of semen, 

 and analogous to the gall-bladder in their functions, until the 

 late Mr. J. Hunter published his opinion that they were not 

 intended to contain semen, but to secrete a peculiar mucus 

 subservient to the purpose of generation. 



He states the following facts in support of his opinion. 



A fluid, very different from semen, is found after death in 

 the vesiculae seminales. 



In persons who have lost one testicle, a considerable time 

 before death, the vesiculae seminales on each side are equally 

 distended with this peculiar fluid. In the case of a person who 

 had a deficiency of the epididymis on one side, and of the vas 

 deferens on the other, the vesiculae were filled with a peculiar 

 fluid ! • 



The sensation arising from redundance of the secretion of 

 the testis, is referred to the testis, and not to the vesiculae 

 seminales. 



In some animals there is no connexion between the vasa 

 deferentia and the vesiculae seminales. 



— And in many others as the dog, there are no vesiculae 

 to be met with. — 



See Observations on certain Parts' of the Animal Economy, 

 by John Hunter. 



