F. A. E. Crew 169 



still was present, and further that towards the end of the table the 

 condition of those ducts is more and more frequc^ntly described as 

 moderately, slightly or weakly developed. In the last 14 cases, th(j ducts 

 were well-developed in 6, moderately developed in 2, and slightly 

 developed in 6, and in all these only spermatic tissue was present in the 

 gonads. 



So that in an otherwise normal male, Mullerian ducts in form and 

 sizie equal to the oviducts of the adult female are found in the presence 

 of actively functioning spermatic tissue. Harms and Meisenheimer 

 claim to have demonstrated that the internal secretion of the male 

 gonad can encourage the development of the accessory reproductive 

 apparatus of the opposite sex, and if this is so, then in such cases the 

 unusual development of the Mullerian ducts may have been a response 

 to the action of the internal secretion of the testes. Experiments con- 

 ducted to test the findings of Harms and Meisenheimer have failed to 

 confirm their results, and there is reason to believe that the occurrence 

 of Mullerian ducts in form and size equal to the oviducts of a mature 

 female, in an otherwise typical male, is an indication that functional 

 ovarian tissue of considerable amount has been present in the gonads of 

 the individual. 



It is of interest to note that, in 1885, Sutton made the following 

 generalisation : 



" When a male frog develops a Bidder's organ or ovary in conjunction 

 with a testis, the Mullerian duct or oviduct then assumes some consider- 

 able size," and from the results of the examination of more than 250 

 specimens of R. temporaria he concluded " that as a rule the amount of 

 development of these ducts is in direct proportion to the size of the 

 Bidder's organ." 



It is gathered from the tables that the presence of spermatic tissue 

 in the gonads is associated with a fuller development of vasa efFerentia 

 and seminal vesicles, and that the Mullerian ducts attain their fullest 

 development only in the presence of ovarian tissue. It is suggested, 

 therefore, that the presence of well-developed oviducts is, in itself, an 

 indication that ovarian tissue either is or has been present in the gonads 

 of the individual possessing them. When once they have attained a 

 considerable size, as they do in association with the development of 

 ovarian tissue, the oviducts persist, even though the ovarian tissue is 

 removed. This can be demonstrated by extirpation of the ovaries, after 

 which the oviducts retain their form and size certainly for several 

 months. They do not attain a fuller development during the breeding- 



