236 



UROGENITAL SYSTEM 



FIG. 231. 



FIG. 231. Diagrams to show the devel- 

 opment of male and female generating organs 

 from a common type (Allen Thomson). 



A. Diagram of the primitive urogeni- 

 tal organs in the embryo previous to sexual 

 distinction: 3, ureter; 4, urinary bladder; 5, 

 urachus; ot, the genital ridge from which 

 either the ovary or testicle is formed; w, 

 left mesonephros; u>, w, right and left 

 mesonephric ducts; m, m, right and left 

 Miillerian ducts uniting together and running 

 with the mesonephric ducts in g.c., the geni- 

 tal cord; tig, sinus urogenitalis; i, lower part 

 of the intestine; d, cloaca; cp, phallus 

 which becomes clitoris or penis; Is, fold of 

 integument from which the labia majora 

 are formed. 



B. Diagram of the female type of sex- 

 ual organs: o, the left ovary; po, epoo- 

 phoron; w, scattered remains of mesoneph- 

 ric tubules near it (paroophoron) ; d G, 

 remains of the left mesonephric duct (canal 

 of Gartner) represented by dotted lines; 

 that of the right side is marked u<; f, the 

 abdominal opening of the left uterine 

 tube; , uterus; the uterine tube of the 

 right side is marked m; g, round liga- 

 ment, corresponding to gubernaculum; i, 

 lower part of the intestine; va, vagina; h, 

 situation of the hymen; C, gland of Bar- 

 tholin (Cowper's gland), and immediately 

 above it the urethra; cc, corpus cavernosum 

 clitoridis; sc, vascular bulb or corpus spongi- 

 osum; n, nympha; /, labium; v, vulva. 



C. Diagram of the male type of sexual 

 organs: /, testicle in the place of its original 

 formation; e, caput epididymis; vd, ductus 

 deferens; W, scattered remains of the meso- 

 nephros, constituting the organ of Giralde's, 

 or the paradidymis; vh, vas aberrans; m, 

 Miillerian duct, the upper part of which 

 remains as the appendix testis, the lower 

 part, represented by a dotted line descend- 

 ing to the prostatic vesicle, constitutes the oc- 

 casionally existing cornu and tube of the va- 

 gina masculina ; g, the gubernaculum; w, the 

 vesicula seminalis; pr, the prostate gland; c, 

 Bulbo-urethral gland of one side; cp, cor- 

 pora cavernosa penis cut short; sp, corpus 

 cavernosum urethrae; s, scrotum; /', together 

 with the dotted lines above, indicates the di- 

 rection in which testicles and epididymis de- 

 scend from the abdomen into the scrotum. 



