F. A. E. Crew 



161 



TABLE I. 



Division I. 



The secondary sexual characters were 

 not typically male 



Group A. One ovary ; one ovo-testis ... 

 Sub-group 1. The ovary was normal iu 



appearance 

 Sub-group 2. The ovary was abnormal in 



appearance 

 Group B. Two ovo-testes 

 Group C. One ovo-testis ; one testis 

 Sub-group 1. The testis was abnormal in 



appearance 

 Sub-group 2. The testis was normal in 



appearance 

 Group D. Two testes 

 Sub-group 1. The testes were abnormal in 



appearance 



Sub-group 2. The testes were normal in 

 appearance 



a: Totals 



= 1 



Of the 40 cases described, 21 were furnished by R. temporaria. This 

 does not mean, necessarily, that this species is more prone to abnor- 

 mality than any other, however, and the explanation of these figures 

 possibly lies in the fact that the Common Grass Frog is used for labora- 

 tory purposes more commonly than others. Only 40 cases have been 

 thought worthy of detailed description, but there is little doubt that 

 similar cases have been encountered in every Zoological Laboratory 

 though unrecorded. Nevertheless, such abnormality must be regarded 

 as very rare, though certainly occurring in all species of the Anura. 



