FORMATION OF THE EXTERNAL ORGANS. 1001 



the rudimentary clitoris or penis, and between the prolonged margins of the groove 

 beneath that organ. This opening, but not the clitoris or penis, is concealed by the 

 large cutaneous folds already mentioned. In this condition, which continues until 

 the twelfth week, the parts appear alike in both sexes, and resemble very much the 

 perfect female organs. The rudiments of Cowper's (/lands are, it is said, seen at an 

 early period, near the root of the rudimentary clitoris or penis, on each side of the 

 genito-urinary passage. 



In the female, the two lateral cutaneous folds enlarge, so as to cover the clitoris 

 and form the labia majora. The clitoris itself remains relatively smaller, and the 

 groove on its under surface less and less marked, owing to the opening out and sub- 

 sequent extension backwards of its margins to form the nymphce. The hymen begins 

 to appear about the fifth month. Within the nymphae, the urethral orifice, as 

 already mentioned, becomes distinct from that of the vagina. 



In the male, on the contrary, the penis continues to enlarge, and the margins of 

 the groove along its under surface gradually unite from the primitive urethral 

 orifice behind, as far forward as the glans, so as to complete the long canal of the 

 male urethra. This is accomplished about the fifteenth week. When this union 

 remains incomplete, the condition named hypospadias is produced. In the mean- 

 time the prepuce is formed, and, moreover, the lateral cutaneous folds also unite 

 from behind forwards, along the middle line or raphe, and thus complete the scrotum, 

 into which the testicles do not descend until the last month of foetal existence. 



The following tabular scheme of the corresponding parts of the genito- 

 urinary organs in the two sexes, and of their relation to the formative 

 rudiments of the common embryonic type, may be useful in fixing attention 

 on the more important points of the subject. 



FEMALE. COMMON EMBRYONIC. MALE. 



Ovai 7 ........ I 7 1 S3 am n . . . repr0dUCti T e } Body of Testicle. 



II. Wolffian body.' 



Irregular vestiges near paro- \ 2. Tubular substance of j Organ of Giralde"s. 

 varium (?) .................. ) the gland ............ \ Vasa aberrautia. 



Duct of Gaertnerinsomeani-) f 3 " *g^ d duct along ^^ ^ rf mig> 



mals ...................... ' (4. Duct below the gland Vas deferens. 



III. Duct of Mtiller. 



FlmM. and FaUopian tube . . !. Ujjp. ^and^part ) Hyd,tM -HjgjjP- d other 



gland .............. ) 



Cornu uteri .................. 2. Free part of duct . . . . { C ^ m l simiS P CUlar 



Uterus and vagina ............ 3. Fused part of both \ 



ducts in the genital j- Sinus pocularis. 

 cord .............. ) 



Female urethra .............. I V. -Pedicle of the allantois ..{ UpP JJ P r e ?a f pl ' StatiC P&rt 



Vestibule .................... V.-Sinus urogenii.lis ........ { 



Glands of Bartholin .......... Common blastema ............ Glands of Cowper. 



VI. Common sexual pro- 

 minence and integumental 

 folds. 

 Corpora cavemosa clitoridis . . 1. Common blastema ____ Corpora cavemosa penis. 



Labia majora ................ 2. Outer integumental \ g crotum 



Nymphse ................... 3. Inner integumental ) Integument of lower surface of 



folds ................ j penis. 



Vestibular bulbs and other erec- ) 4. Common blastema j Bulb and corpus spongiosum 



tile tissue .................. ) " \ urethrse. 



VII. Peritoneal folds and 



gubernacular bands. 

 Canal of Nuck ................ 1. ^f^l peritoneal j. Processu8 vagilial i s . 



Ovarian ligament ............ *-lS tetet" J^l-" connecting testicle and 



nan body .............. j globus minor. 



Round ligament of uterus .... 3. Band rom } Gubernaculum testi-. 



