FALLOPIAN TUBE OR OVIDUCT (DEVELOPMENT). 



CIS 



fcrence, the sent of normal impregnation ; 

 while such a view is opposed to those nu- 

 merous observations upon the mammalian 

 ovum generally, which show, that before the 

 ovum quits the oviduct, the developmental 

 changes in it are already advanced many 

 stages, while, by the time that it arrives at 

 the uterus, the opportunity for impregnation 

 hns already passed away for that occasion. 



DEVELOPMENT OF THE FALLOPIAN TUBE. 



Whatever difference of opinion may exist 

 regarding the origin of the excretory duct of 

 the male generative gland, there appears to be 

 no doubt, that in birds at least the correspond- 

 ing part in the female has its commencement 

 in a structure which, as soon as it can be 

 recognised as a distinct tube, is altogether 

 separate from the Wolffian body. Tin's is 

 called after its first observer, tne duct of 

 Miiller* (jig. 400. g). 



The mode of origin of this duct has been 

 already partly described in the account which 

 has been given of the formation of the Paro- 

 varium (p. 594-.). Its development may be 

 most conveniently traced in birds, where it 

 can be easily shown that the oviduct is not a 

 metamorphosis of the excretory duct of the 

 Wolffian body, but may be distinguished lying 

 near it, in the form of a tolerably thick tube ; 

 which at first ends in a closed extremity, but 

 afterwards exhibits a wide orifice. It runs 

 along the outer side of the Wolffian body, 

 while its infundibulum, which is soon distin- 

 guishable, extends beyond and is entirely se- 

 parate from that body. 



The oviducts appear from the first in the 

 form of white cylinders on both sides. They 

 do not grow from below upwards, but are 

 formed in their entire length from the com- 

 mencement ; nor are they constructed out of 

 a membranous lamina, rolled together, as 

 Meckel supposed ; but are in the beginning 

 solid, and become gradually hollowed out into 

 a tube. In this way also is formed the infun- 

 dibular opening of the tube into the abdomi- 

 nal cavity. 



Two oviducts exist originally in all birds, 

 but as in this class the right ovary shrinks 

 and disappears, so the right oviduct becomes 

 lost, by gradually contracting and shortening 

 from above downwards, j- 



In mammals, before the distinction of sex 

 becomes apparent internally, there is seen, 

 running along the Wolffian body of each side 

 in every embryo, a duct, which, according to 

 Miiller, may represent either a vas deferens, 

 or an oviduct. These ducts lie upon opposite 

 sides of the germ glands, which may become 

 afterwards testis or ovary. 



Soon afterwards the internal organs begin 

 to exhibit a distinction of sex. This is indi- 



* See Miiller's Bildungsgeschichte der genita- 

 lien. Diisseldorf, 1830. 



f Prof. Qtiekett has pointed out to me, in the col- 

 lection of the Royal College of Surgeons, a remark- 

 able preparation by Mr. Tegetmeir, in which the 

 right oviduct is developed in the common fowl. 



cated in the future male by the duct, which 

 runs along the outer side of the Wolffian 

 body, sending off a white granular projection, 

 extending towards the testis, which is met by 

 a similar projection, given off by the upper 

 end of the testis, and these two by their 

 union form the rudiments of the epididymis. 

 So that in the male mammal a new connexion 

 is established between the duct, which after- 

 wards becomes vas deferens, and the testis, 

 without any agency from the Wolffian body, 

 but through the development of new material. 



In the female these projections are wanting, 

 both from the excretory duct and from the 

 ovary. The latter remains attached only to 

 the Wolffian body by a simple fold. The up- 

 per end of the duct, which runs over the 

 Wolffian body, projects somewhat beyond that 

 body inferiorly, and terminates here in a glo- 

 bulur swelling, in which an aperture is formed 

 at a later period. 



As the Wolffian body becomes atrophied 

 the portion of the duct which takes its course 

 over it, and which was previously straight, 

 begins to be tortuous in the male, while in the 

 female it remains straight, but becomes wider. 

 Out of corresponding portions of the duct 

 are formed, in the mate, the head of the epi- 

 didymis, and in the female the infundibular 

 end of the tube, while the inferior free por- 

 tion of the duct, after it has quitted the 

 Wolffian body becomes converted, in the male, 

 into the vas deferens, becoming at the same 

 time more and more elongated ; but in the 

 female the corresponding portion of the duct 

 is transformed into the inferior division of 

 the tube, or into the cornu of the uterus.* 



In this stage of its development the inci- 

 pient Fallopian tube is only beginning to be 

 recognisable. It circumscribes the diminish- 

 ing Wolffian body on its outer side in the 

 form of a bow. Above the superior opening 

 extends beyond that body, while below the 

 short free portion becomes conjoined with that 

 of the opposite side to form a single tube. 

 These ducts have throughout the sume breadth 

 up to their union with each other. 



A division of the duct into uterus or cornn, 

 and narrower Fallopian tube, is still nowhere 

 perceptible, and the place of this latter divi- 

 sion is only as yet indicated by the addition 

 of the substance which afterwards becomes 

 ligamentum rotundum. Between the oviduct 

 and the ovary lies the atrophied Wolffian body 

 of a dirty yellow colour, in part surrounding 

 the ovary ; but notwithstanding this conti- 

 guity the tubuli of the Wolffian body form no 

 union between the Fallopian tube and the 

 ovary. The duct, or future Fallopian tube, 

 which had previously preserved a perpendi- 

 cular direction, now takes, with the rest of 

 these parts, a more sunken position. But it 

 still lies close to the Wolffian body, from 

 which it is separated by a narrow fold of 

 peritoneum. 



* The researches of Kobelt upon this subject 

 have been already explained under the head of 

 development <>f tin- I'arovannm. 



R n 3 



