2040 



HUMAN ANATOMY. 



persists, the intervening portion of the Miillerian duct is represented by Rathke's 

 duct. Since the prostate gland arises as an outgrowth from the urogenital sinus 

 (page 1979), it has no genetic relation with the seminal ducts. 



Descent of the Testes. — The development of the sexual glands, in both 

 sexes, is attended with conspicuous migration from their original position on either 

 side of the upper two lumbar- vertebrae, opposite the lower pole of the kidney. In 

 the case of the testis, this migration is so extensi\e that by birth the organ usually has 

 passed through the abdominal wall and entered the scrotum, having completed 

 its so-called descent. 



Certain peritoneal folds (mesenteries) and fibro-muscular bands (ligaments) merit 

 brief description, since they are more or less concerned in the migration of the sexual 

 glands. The Wolfftan body is enclosed and attached to the posterior body-wall 

 by a fold (niesonephridiuni), of which the upper elongated end is continued to the 



Fig. 1 719. 



MD 



WD 



Ur CG Pr 



Diagrams illustrating differentiation of two sexes from indifferent type. A, Indifferent : G, sexual gland; WD, 

 Wolffian duct; WT, WT, groups of Wolffian tubules; MD, Miillerian duct; RD, renal diverticulum,' C, cloaca; 

 G, gut; A, allantois. B, Male: T, testicle; VE. vasa efferentia ; GM. globus major; VD, vas deferens; Pa, para- 

 didymis ; V'A, vas aberrans ; SV, seminal vesicle ; AT, appendix testis ; AE, appendix epididymidis ; B, bladder ; PU, 

 prostatic utricle; Pr, prostate; Ur, urethra; CG, Cowper's gland; CC, corpus cavernosum ; R. rectum ; RD, renal 

 duct ; K, kidney. C, Female : O, ovary ; Ov, oviduct ; F, fimbria ; U, uterus ; V, vagina ; DEp, duct of epoophoron ; 

 TEp. tubules of epoophoron; Po, paroophoron; HM, hydatid of Morgagni ; GD Gartner's duct; BG, Bartholin's 

 gland; C, clitoris ; K, kidney; R, rectum. (Modified front IViedersheim.) 



diaphragm {plica phrenico-mesonephricd) and the lower to the abdominal wall in 

 the inguinal region {plica inguino-mesonephrica) . The early sexual gland is also 

 provided with a mesentery {mesorchium. or mesovarium), that abo\'e and below is 

 continuous with folds that pass from the upper and lower poles of the gland to the 

 mesentery of the mesonephros. Within the inferior plica, of the two much the better 

 marked, lies a fibro-muscular strand (the ligament of the testis or ovary), that below 

 is attached at first to both the Wolffian and Miillerian ducts. Later, owing to the 

 atrophy of the one or the other of these ducts, according to sex, the ligament of the 

 testes remains connected with the Wolffian duct and the ligament of the ovary with 

 the Miillerian duct. 



A second band of muscular tissue appears within the lower part of the inguino- 

 mesonephric fold, and has its upper attachment also to the Wolffian and Miillerian 

 ducts at a point about where they receive the insertion of the ligament of the testes or 

 ovary. The lower end of the band blends with the subperitoneal tissue of the anterior 

 abdominal wall in the vicinity of the future abdominal ring. This band, the genito- 



