478 URO-GENITAL SYSTEM. 



the third month, if it is to be a testicle, the canaliculi of the 

 Wolffian body penetrate into its substance, there multiply, and 

 become the seminiferous tubulL At the same time the other 

 portion of this body is atrophied, and the remaining por- 

 tions with its excretory canal constitute, the former certain 

 rudimentary organs (non-pediculated hydatid of Morgagni, 

 corpus innominatum of Giraldes), whilst from the latter are 

 formed : the excretory ducts of the testicle, caput or head 

 and body of the epididymis, vas deferens, with numerous 

 more highly convoluted tubes, which are the remains of the 

 appendages of the Wolffian body; of these the most note- 

 worthy and constant becomes the vas aberrans. 



In this way the internal genital organs of man essentially 

 spring from the Wolffian body ; and form the testicle, vesiculse 

 seminales, and, finally, the ejaculatory canals; in brief, form 

 all the organs that are comprised between the seminal gland 

 and the genito-urinary sinus (prostatic portion of the urethra). 

 The Miillerian duct (see p. 518) is completely atrophied in 

 man ; its only remaining trace is found in the two extremi- 

 ties that form the pediculated hydatid of Morgagni, and the 

 central portion, which unites with that of the opposite side to 

 form the utriculus prostatieus. We shall see that the Miil- 

 lerian ducts represent the whole of the genital organs in 

 woman, and especially form the womb, by the fusion of the 

 two inferior portions of the duct on each side, in the same 

 way that the prostatic utricle is formed in man : the utricu- 

 lus prostatieus and the uterus are homologous organs. 



A. Testicle and its excretory canals. Formation of the 

 spermatic fluid. 



a. The seminiferous tubes of the testicle are sinuous tubes, 

 tortuous like the tubes of Ferrein in the cortical substance 

 of the kidney, and terminate at the posterior edge of the tes- 

 ticle in what is called the corpus Highmori (Fig. 131, CA), 

 an eminence of compact fibrous tissue, wherein the seminif- 

 erous tubes cross (rete testis) to go to the excretory canals 

 that form the epididymis. 



The seminiferous tubes are quite numerous : 500 or 1000 

 have been counted in each testicle ; they appear in the form 

 of tubes with thin walls, almost entirely filled with polyhedral 

 epithelium. This epithelium produces the spermatic fluid, 

 whose secretion is temporary and not continuous. The testi- 

 cle is inactive in childhood and old age. At the period of 

 puberty, among the epithelial cells of these tubes, quite 



