594 



UTERUS AND ITS APPENDAGES. 



of peritoneum, after investing the Fallopian 

 tube, passes off towards the ovary, to form 

 the posterior duplicature which encloses the 

 vessels proceeding to that organ, will be found 

 a small plexus of white tortuous tubes, (fig. 

 403. a, b,c) arranged somewhat in the form 

 of a cone whose apex is directed towards the 

 hilum of the ovary /, and its base a c a to- 

 wards the Fallopian tube h. The entire or- 

 gan measures about one inch in breadth, and 

 is composed of J2 20 tubules 0'15 0'2'" in 

 diameter. 



The tubes which contain nothing but a 

 clear fluid consist of fibrous membrane, lined 

 by a single layer of pals, cylindrical, epithe- 

 lial cells. These tubular canals are not 

 known to have any direct communication 

 with the ovary. 



That the parovarium is formed out of the 

 Wolffian body does not now appear to admit 

 of doubt. It has been usually considered 

 that the Wolffian bodies are organs peculiar 

 to foetal life, and that they afterwards entirely 

 disappear in both sexes. Hence no special 

 investigations have been undertaken with a 

 view to ascertain their ultimate fate. Meckel 

 indeed compared them to the epididymis. 

 Rathke believed that they became epididymis 

 in the male, and disappeared in the female ; 

 while Rosen miiller, who discovered the paro- 

 varium, compared this body to the epididy- 

 mis. Some general conjectures also have 

 pointed in themalesexto thevascu/a aberrantia 

 of the epididymis, and in the female to the or- 

 gan of Rosenmiiller and the ducts of Gartner, 

 as the supposed remains of the Wolffian body. 

 Nevertheless it is, according to Kobelt, an 

 undoubted anatomical fact that each pretended 

 ephemeral structure not only exists through 

 the whole of life in both sexes, but that it 

 absolutely increases up to its highest state 

 of perfection, and first suffers a gradual re- 

 trogression, after the extinction of the repro- 

 ductive function, but never entirely disappears. 



The signification and true homologies of 

 this singular organ cannot be understood 

 without first briefly examining the mode of 

 formation and development of the Wolffian 

 body, and tracing its relation to the genera- 

 tive gland and Fallopian tube. In this exa- 

 mination it is also of consequence to compare 

 the progressive steps of formation of those 

 parts with the corresponding structures in the 

 male. 



The Wolffian body is most readily exa- 

 mined in the chick, (figs. 399, 400.) Here 

 during the third day of incubation are formed 

 two canals which extend along the sides of 

 the vertebral column, from the heart to the 

 posterior extremity of the body. To the 

 inner side of each canal is attached a series of 

 blind pouches (fig. 399. c and 400. b), which 

 during the next two days become lengthened 

 and convoluted. These together constitute 

 the Wolffian body. Behind them, and formed 

 independently at a somewhat later period, lie 

 the kidneys (Jig. 399. and 400. a) and supra- 

 renal bodies, (fig. 399. /, 400. d) and as these 

 increase, the Wolffian bodies diminish. The 



testes (fig. 399. e) and ovaria (fig. 400. c) 

 are developed upon the inner border, and in 

 front of the corpora Wolffiana. 



Fig. 399. 



Kidneys, Wolffian bodies, and testes of an embryo 

 bird. Magnified. (After Miiller.) 



a, kidney ; b, ureter ; c, Wolffian body ; d, excre- 

 tory duct of the latter, which, according to the 

 views of Mtiller and Kobelt, afterwards becomes the 

 vas deferens; e, generative gland, afterwards be- 

 coming testes; /, supra- renal capsules. 



In the female chick, according to Miiller, 

 there is always seen an oviduct (fig. 400. g), 



Fig. 400. 



Kidneys, Wolffian bodies, ovaries, and oviducts of a 

 foetal bird, at a period when both oviducts are still 

 of nearly equal size. Magnified. (After Miiller.) 



a, kidney ; b, Wolffian bod}', c, ovary, the right * 

 rather the smaller; d, supra-renal capsule ;/, ex- 

 cretory duct of the Wolffian body, which in the 

 female becomes obliterated, but in the male is con- 

 verted into vas deferens ; g, duct of Miiller, after- 

 wards oviduct or Fallopian tube. 



* The drawing has been reversed in engraving. 

 The left, therefore, should be here the right side. 



