1432 



VESICUL/E SEMINALES. 



deferentia, which, as may be seen by reference 

 to the comparative anatomy cited above, is 

 the case with all the lower animals readily 

 procurable, alive, and in functional activity, in 

 this country. The best evidence that com- 

 parative anatomy affords on the subject is, 

 that, in the elephant, vesiculse seminales, join- 

 ing the vas deferens just as in man, coexist 

 with unmistakeable seminal reservoirs. If the 

 vesicula; were merely receptacles of semen 

 their presence here would be quite superero- 

 gatory, and contrary to Nature's usimH'ashion. 

 It adds to the signification of this fact, that 

 the junction of the ducts occurs below the 

 enormous ampulla, that is, between it and the 

 urethra ; so that the ampulla must be filled 

 before any semen could be regurgitated into 

 the vesiculse. 



Still, as spermatozoa are occasionally found 

 in the human vesiculae seminales, microscopic 

 evidence, of itself, is not able to give us that 

 complete negation of the old and widely spread 

 view of the functions of the vesicular which 

 1 have ventured upon above. And here the 

 acute observations, unaided by the microscope, 

 of the immortal Hunter, of themselves suf- 

 ficient to prove this negation almost to a 

 certainty, afford such an accession of proof.as 

 cannot fail to be convincing. He examined 

 the vesiculae in several subjects in which one 

 testicle had been extirpated a long time before 

 death, and he found in every case that the 

 rrs/cula of the castrated side was as full as that 

 of the other. One of the cases examined by 

 him was a married man in whom he had ex- 

 tirpated the left testicle a year before his death. 

 " On examining the body, the vesiculae were 

 both found nearly full, more especially that 

 on the left side, which might have been acci- 

 dental." To remark that the vesicula of the 

 castrated side was fuller than the other seems 

 to be proving too much (he observed the 

 same in one other case) ; but the rest of his 

 cases show clearly that this was, as he says, 

 accidental. These invaluable observations of 

 Hunter, together with his comparison of the 

 thick brownish mucus found in the vesiculae, 

 with the extremely different, milky, slightly 

 viscid semen in the vas deferens of the same 

 subject, and the contrast observable in the 

 two fluids by aid of the microscope, a few 

 scattered spermatozoa or none at all in the 

 one, crowded mjriads in the other, lead 

 irresistibly to the conclusion that the vesiculae 

 seminales are not reservoirs of semen. 



2dly, They form part of the generative ap- 

 paratus. This is pretty clearly ) proved by 

 Hunter, by observations made on those animals 

 that have periods of rut or sexual excitement 

 alternating with periods of sexual quiescence 

 or impotency, such as the stag, the mole, and 

 the land-mouse. In these animals the vesicula? 

 seminales, in common with the testicles, pro- 

 state gland, &c., are exceedingly small during 

 the period of impotence, and enlarge enor- 

 mously and rapidly for the season of rut. In the 

 mole they are hardly discernible in v\ inter, but 

 become enormously large in spring. Conclusive, 

 however, as this proof appears, prima fade, 



to be, it is somewhat weakened by the fact 

 that much the same thing happens, in various 

 animals, to other parts which would scarcely 

 be enumerated as belonging to the generative 

 apparatus, such as the horns of the stag, the 

 comb of the cock, &c. Yet, adding to the 

 fact of this periodic enlargement and diminu- 

 tion the anatomical position and connections 

 of the vesicula?, together with their absence 

 in tfie female, there is constituted a very 

 satisfactory proof that they form part of the 

 male generative apparatus. 



These conclusions, however, merely bring 

 us two steps nearer to a definite knowledge of 

 the exact office fulfilled by the organs in ques- 

 tion. I now proceed to adduce such other ob- 

 servations as I have been able to make, or 

 have found upon record, as may aid in forming 

 an hypothesis as to their positive function, 

 or may appear interesting. 



The mucus found in the vesiculae is, as will 

 readily be admitted from what has been said 

 above, undoubtedly secreted by their glandular 

 parietes. This is still better proved by a case 

 of Hunter's, where, as a congenital defect, 

 they had no outlet (nor inlet), and yet were 

 full of mucus. This case shows also that 

 they have the power of re-absorbing their 

 secretion, or at least renders it highly probable. 

 A mucus in all respects similar is usually 

 found in the part of the vas deferens imme- 

 diately contiguous to the junction of the duct 

 of the vesiculae. This is very probably se- 

 creted by the walls of this part of the vas 

 in the horse there is no doubt of it. The mu- 

 cus of the vesiculae is very thick and viscid in 

 all animals, but more so in some than in others. 

 I have examined it carefully in the guinea- 

 pig, in which animal it is remarkably thick ; 

 but there is a difference, in this respect, be- 

 tween that which is near the outlet and that 

 which is at the fundus, it being thickest in the 

 former position and gradually thinner towards 

 the latter. It is transparent, granular, and 

 has a faint opaline blue colour. I found 

 that it rapidly solidified upon being squeezed 

 out of the vcsiculoe,' and that too even when 

 not exposed to the air and when not subjected 

 to any remarkable diminution of temperature, 

 when lying, in fact, in the urethra of the 

 animal just killed. The mucus contained in the 

 vesicnlas also solidified more though slowly 

 that in the fundus most slowly, and the rest 

 in gradual progression up to that near the 

 outlet. In opening the abdomen of a guinea- 

 pig, it is almost impossible to avoid com- 

 pressing the vesiculae, and probably from 

 this cause a considerable quantity of the 

 mucus is forced into the urethra, where I 

 always found it forming a solid mass as hard 

 and elastic as the cartilage of a ray-fish, 

 and moulded to the shape of the urethra : this 

 \\ithin a few minutes after the death of the 

 animal. Now, this is just the contrary to 

 what, according to Hunter, is the case with 

 emitted semen, which becomes more and 

 more fluid under exposure. I was, however, 

 highly interested to observe that if the vasa 

 deferentia and vesiculae be compressed at the 





