10 Dorothy Price and Richard Pannabecker 



the number and size of the buds but, in general, the prostatic 

 buds were more numerous and larger in explants with testes or 

 with testosterone. 



Discussion 



The results of the culture experiments indicate that a hor- 

 mone from the foetal testes maintained the Wolffian ducts, 

 stimulated the formation of the primordia of the seminal 

 vesicles and their growth, and caused an increase in the num- 

 ber of prostatic buds. These findings extend and corroborate 

 some of the observations of Wells and his co-workers (Wells 

 and Fralick 1951; Wells, Cavanaugh and Maxwell, 1954) 

 in castrated rat foetuses. They concluded that testicular 

 androgen stimulates the prenatal growth of male rat accessory 

 reproductive organs but that they could not determine 

 whether this androgen caused the development of the pri- 

 mordia of these glands. They also observed absence of the 

 flexure of the seminal vesicles and loss of the epithelium of the 

 ductus deferens following castration and attributed this to 

 two factors, the absence of the testes and impairment of 

 deferential circulation due to surgical injury (Wells and 

 Fralick, 1951). Testosterone treatment, however, prevented all 

 of the observed effects of castration. In unilateral castration 

 they found effects on the ductus deferens and the seminal 

 vesicle on the operated side in some foetuses, but they con- 

 sidered that these results were due to circulatory impairment 

 and did not support the idea of local action of a diffusing 

 testis hormone. 



Explantation of foetal rat reproductive tracts at ages from 

 15-5 to 18-5 days gave results that suggest that the retention 

 of the Wolffian ducts and the development of seminal vesicle 

 primordia may normally depend upon testis hormone. Under 

 culture conditions, this hormone reached other parts of the 

 tract by diffusion and produced local effects on Wolffian 

 ducts and seminal vesicles in unilaterally castrated explants. 

 Further, the results of detaching and replacing testes on the 



