DEVELOPMENT OF THE GENITAL ORGANS. 109 



Up to this point no difference of sex is perceptible; but from this stage, 

 towards the commencement of the third month, the internal organs of the 

 female and male begin to assume a different appearance, 



Female Organs. The genital gland, in its development into an ovary, becomes 

 more lengthened and assumes an oblique position, by which characters it can 

 be distinguished from the testicle, about the ninth or tenth week. The ovary 

 is at first situated internal and anterior to the Wolffian body. As that body 

 disappears the ovary descends towards the inguinal region. It passes into the 

 pelvis towards the end of foetal life. The ovules and Graafian follicles are 

 derived from the genital gland, but according to His the stroma of the ovary is 

 furnished by the Wolffian body. 



The Fallopian tube is formed by the portion of the duct of Muller, which lies 

 above the lumbar ligament of the Wolffian body. This duct is at first com- 

 pletely closed, and its closed extremity remains permanent, forming a small 

 cystic body attached to the fi mbriated end of the Fallopian tube, and called the 

 " hydatid of Morgagni." Below this, a cleft forms in the duct, and is developed 

 into the fimbriated opening of the Fallopian tube. 



Below this portion of the duct of Muller, that body on either side, and the 

 ducts of the Wolffian body, are united together in a structure called "the genital 

 cord," in which the two Miillerian ducts approach each other, lying side by 

 side and finally coalescing to form the cavity of the vagina and uterus. This 

 coalescence commences in the middle, corresponding to the body of the uterus. 

 The upper parts of the Miillerian ducts in the genital cord constitute the cornua 

 of the uterus, little developed in the human species. The only remains of the 

 Wolffian body consist in a structure (parovarium or organ of Eosenmiiller) 

 which can usually be detected lying between the ovary and Fallopian tube, and 

 consisting of a group of tubules converging to a single duct, which is some- 

 times of considerable size and runs for some distance in the broad ligament. 



About the fifth month an annular constriction marks the position of the neck 

 of the uterus, and after the sixth month the walls of the uterus begin to thicken. 



The round ligament is derived from the lumbar ligament of the Wolffian 

 body, the superior ligament of the genital gland becomes the cord which 

 attaches the ovary to the fimbriated extremity of the Fallopian tube, the peri- 

 toneum constitutes the broad ligaments, the superior ligament of the Wolffian 

 body disappears with that structure. 



Internal Organs in the Male. 1. The genital gland, in its development Into a 

 testicle, becomes rounded and thick, and is more vertical than the ovary is in 

 its early state. The tubuli seminif'eri are early visible, being at first short and 

 straight, and then gradually assume a coiled arrangement. The tunica albu- 

 ginea is formed about the third month. 



2. The Mullerian ducts disappear in the male sex, with the exception of their 

 lower ends. These unite in the middle line, and open by a common orifice into 

 the uro-genital sinus. This constitutes the utriculus hominis or sinus prostaticus. 



3. The head of the epididymis, its canal, tha vas deferens and ejaculatory 

 duct, are formed from the canals and from the duct of the Wolffian body.- 



The remains of the Wolffian bodies also form the vas aberrans, and a struc- 

 ture described by Giraldes 1 and called after him, "the organ of Giraldes," 

 which bears a good deal of resemblance to the organ of Rosenmiiller in the 

 other sex. It consists of a number of convoluted tubules lying in the cellular 

 tissue in front of the cord and close to the head of the epididymis. 



The descent of the testis and the formation of the gubernaculum are de- 

 scribed under the Male Generative Organs, in the body of the work. 



The external organs of generation, like the internal, pass through a stage in 

 which there is no distinction of sex (Fig. 67, I, II, III). We must therefore 



1 Journ. de Fhys., 1861. 



