Organ Culture Studies of Reproductive Tracts 11 



tracts indicate that surgical injury can be ruled out as a 

 significant factor in general Wolffian duct retrogression. 



The question of the relation of testis hormone to the 

 development of the prostate glands cannot be definitely- 

 answered. Prostatic buds developed in gonadless tracts 

 which had been explanted before the appearance of the 

 primordia and this development was reported also for cas- 

 trated foetuses (Wells, Cavanaugh and Maxwell, 1954). In 

 culture, these buds formed in only one tract (with testes) 

 which was explanted at 15+ days, but this result may repre- 

 sent only slowed development. It seems probable that the 

 prostatic region of the urethra is subjected to the influence of 

 testis hormone in the foetus as early as 15+ days, and it may 

 soon be conditioned to produce a few prostatic buds even in 

 the absence of further hormone stimulation. The hormone, as 

 a diffusible agent, would act to bring out an underlying organ- 

 ization of the urethra. However, such an interpretation is 

 complicated by the fact that prostate glands developed in 

 foetal female tracts after explantation (Pannabecker, 1956). 



The conclusions as to the significance of foetal rat testis 

 hormone in relation to the Wolffian ducts, seminal vesicles and 

 prostate glands and the observation of local action of testis 

 hormone are in agreement with the findings of Jost (1947, 

 1950, 1953) in his extensive studies on castrated foetal rabbits. 

 His results showed, however, that prostatic buds did not 

 develop when castration was performed at the youngest ages. 

 He and his collaborators (Jost and Bergerard, 1949; Jost and 

 Bozic, 1951) reported the retrogression of the Wolffian ducts 

 in cultured fragments of gonaducts of foetal rats. Raynaud 

 and Frilley (1946, 1947, 1950) reported that following X-ray 

 destruction of the testes in mice, the accessory reproductive 

 glands were smaller or absent and a unilateral effect was 

 observed when only one testis was destroyed. 



The direct stimulating effects of oestradiol on the Wolffian 

 ducts and on seminal vesicle development in a few gonadless 

 explants is of interest, since it duplicates the results obtained 

 in female rat foetuses when the mothers were injected with 



