VESICULA PROSTATICA. 



1427 



able width of the vaginal orifice, and the 

 almost female uro-genital canal, that we had a 

 true female before us. The testicles (a a), 

 which remain in the abdominal cavity, possess 

 a true ala vespertilionis, and also exhibit a 

 more solid parenchyma than usual, although 

 they consist of spermatic gland-canals. Only 

 the epididymis and vas deferens are distinctly 

 male in character. The latter (d d) takes the 

 same course as in the instance previously de- 

 scribed, except that the lower ends are com- 

 pletely buried in the anterior wall of the body 

 of the uterus and the vagina (like the Gart- 

 ner's ducts), and the seminal vesicles are much 

 smaller. 



In this way we acquire a conviction that the 

 Weberian organ, by a further development, is 

 formed not into a uterus only, nor yet into 

 a vaiina only but, at least as a rule, into 

 both these structures simultaneously. Hence 

 we need not scruple to regard it as the mor- 

 phological equivalent of both. So that, the We- 

 berian organ is the male sinus genita/is, which in 

 the female animal undergoes a further develop- 

 ment into the vagina and the uterus. 



It is certainly an important guarantee for 

 the correctness of this theory, which had been 

 casually expressed for some time by Bim- 

 baum *, and is now from a communication to 

 me by letter shared in by my friend H. 

 Meckel, that it had been applied by E. H. 

 \\eber-f- himself, to the vesicula prostatica of 

 the rabbit. From a comparison with the 

 female organs, he came to the conviction, that 

 it represented the uterus with the vagina ; 

 but unfortunately he neglected to extend this 

 view, and in the other Mammalia he regards 

 the vesicula prostatica as only a masculine 

 uterus. 



We have mentioned above that the lower 

 part of the Weberian organ is occasionally 

 contrasted with the upper, either by an annular 

 constriction, in man, or by a singular width, 

 as in the horse : or that the contrast may be 

 limited to particular individuals, as in the 

 goat. It is evident that this can only be 

 explained as a transverse severance into 

 uterus and vagina, a condition which cer- 

 tainly is never normally completed in the 

 male animal. 



And when, as sometimes happens in the 

 horse, the upper section altogether disappears, 

 we need have no scruples in regarding the 

 lower remaining part as the vagina only.| In 

 such instances the theory of Meckel holds 

 good : a theory which was but too widely ap- 

 plied by its founder. 



Hence it may be laid down as a law, that 

 the upper part of the Weberian organ, which 

 corresponds to the uterus, and which also 

 shows such great variations in the develop- 



* Beschreibung und Kritik einer eigenthumlicho 

 Bilduugshemmung. Giessen, 1848, S. 15. 



t Zusatze, &c., S. 8. 



j In some pathological instances a vagina exists 

 without an uterus ; as was detailed by Ricco (Cenno 

 Stor. su di un neutro uomo), and quoted by 

 son (1. c. p. 703.). 



ment of its horns, is less persistent than the 

 under part of the vagina. Thus the question 

 may arise whether the Weberian organ, when 

 it is devoid of cornua, still possesses an upper 

 or uterine part. In order to decide this with 

 certainty, every such instance would require 

 a careful analysis, assisted by the historv of 

 its normal and abnormal development. But 

 as a rule we are justified in supposing that the 

 Weberian organ is, as was stated above, and as 

 is constantly rendered indubitable by the pre- 

 sence of cornua, both vagina and uterus. 



I have here, without further discussion, 

 passed over the question, whether a com- 

 plete absence of the vagina may not obtain in 

 the male mammalia ; a supposition which is 

 required by the unconditional reception of 

 Weber's theory. And this has been done 

 because an assumption of this kind only leads 

 to doubtful morphological hypotheses ; the 

 necessity of which seems very inconceivable 

 after the positive results we have already 

 obtained. Wherever the female individual 

 possesses a vagina the Weberian organ is, at 

 least in part, vagina also ; even where, as in 

 the beaver, the exterior appearances speak by 

 no means strongly in its favour. 



But it is certainly otherwise in the case of 

 those Mammalia whose females lack the vagina. 

 Here I do not so much refer to the mono- 

 tremata, who, in the development of their 

 genitals, approach much more closely to the 

 birds than to the other Mammalia, and per- 

 haps are devoid of a proper uterus : but rather 

 to the elephant, in the female of which, as 

 Mayer has lately shown *, the orifice of the 

 urethra is only separated by a very small fold 

 from the external orifice of the uterus, and the 

 vagina is absent. The whole genital canal is 

 here metamorphosed into uterus. In like 

 manner the Weberian organ of the young male 

 certainly corresponds to the uterus solely. 

 In any case, such instances constitute but 

 rare exceptions, and do not affect the general 

 interpretation of the Weberian organ. 



After all that we have now learnt concern- 

 ing the morphological import of the Weberian 

 organ, it is scarcely necessary to state, that 

 it, or rather the embryonic part out of 

 which it is developed in the male animal, 

 is present in all mammalia up to a certain 

 period of foetal life. Where it is afterwards 

 absent it must be attributed to a retrograde 

 process of development ; which to some ex- 

 tent appears to occur very early, as in the 

 sheep. The date and degree of this retro- 

 gression is shewn by the anatomical de- 

 velopment of the Weberian organ. In some 

 instances it preserves both its embryonal 

 form and size ; in others it continues to in- 

 crease even after birth, as was especially men- 

 tioned of the rabbit. 



I recur once more to this animal, because 

 it, with its congeners, is not only conspicuous 

 on account of the described connection be- 



* Beitrage zur Anatomic der Elephanten ; iu deu 

 Nov Act. Leopold, t. xxii. P. II. S. 38. 



2 Y 2 





