362 DR 1). BERRY HART. 



of course, long been held by some observers that the duct of 

 Milller was pronephric. (Sedgwick.) 



We may say, then, that the early foetus is not hermaphroditic 

 or double-sexed. There is never ovary and testis, but only an 

 indifferent gland at first. The essential point seems to be that 

 we first get the Wolffian bodies or temporary kidneys formed, 

 and these are developed apparently as sexual kidneys, which 

 wither in advanced vertebrates when the ova and spermatozoa are 

 fairly formed. They are utilised, as far as possible, in the 

 development of the conducting parts of the genital tract, and 

 thus from pronephric epithelium the :\Iilllerian duct probably 

 arises, while the whole of the mesonephric duct and part of the 

 mesonephric tubules are utilised for the testis. 



The conducting part of the genital tract is thus practically 

 an adaptation of the Wolffian scatfolding, and the persistence in 

 the female of such well-marked functionless portions as the 

 epoophoron and paroophoron is to be associated with the fact 

 that the mesonephros is the best developed part of the Wolffian 

 body, its duct is taking part in the development of the female 

 fcetus as late as the third and a half month. If we grant the 

 pronephric Anlage of the Miillerian duct, the more marked 

 atrophy of the latter in the male is to be correlated with its 

 origin from a more rudimentary part of the Wolffian system. 



B. — The homolof/y of the male and female sexual function. 



An interesting parallel can be drawn between tlie male and 

 female sexual functions. The female supplies an ovum which 

 is discharged along the Fallopian tube, and, if impregnated, is 

 developed, as a rule, in the uterus. The ovum is a modified cell 

 from the specialised ca?lomic epithelium, i.e. is a peritoneal cell, 

 and is passed along a duct which, if not pronephric, is at least 

 modelled on a pronephric or mesonephric type. The discharge 

 of the ovum is probably a specialised Wolffian function. The 

 spermatozoon is also part of a modified peritoneal cell, and is 

 discharged along the vas deferens, i.e. Wolffian duct. The dis- 

 charge of the spermatozoon is thus practically a specialised 

 Wolffian function. 



