Abnormalities of Reproductive System found in Frogs. 241 
XXII.-A Description of certain Abnormalities of the Reproductive 
System found in Frogs, and a Suggestion as to their possible 
Significance. By F. A. E. Crew, M.B., Assistant in the Natural 
History Department of the University of Edinburgh. 
(With Plates.) 
(Read 23rd February 1920. Received 12th December 1920;) 
DurinG the last two years I have had the opportunity of examining four 
specimens of frogs (Rana temporaria and R. esculenta) in which well-marked 
abnormality of the reproductive system was present. Two of these were 
handed to me by Professor J. H. Ashworth, to whom I am greatly indebted 
both for the specimens and for much inspiring and kindly interest. All four 
were met with in the course of the ordinary work of the Practical Zoology 
Class within the University. 
When the examination of these specimens was finished: and _ their 
description completed, hearing that Mr Julian S. Huxley had met with 
a similar case, I wrote to him, briefly describing my own cases and asking 
if his confirmed certain conclusions at which I had arrived. In answer, 
came not only every sort of information, but also three frogs all showing 
well-marked abnormality. Mr Huxley had begun the examination of one 
of these, but on learning of my interest, he immediately, and with 
characteristic grace, handed the specimen and all his notes concerning it 
to me. A second frog, similarly met with during the ordinary class work 
at Oxford, had been preserved for future description, while the third was 
a specimen which had been incompletely described by A. F. S. Kent in the 
Journal of Anatomy and Physiology, vol. xix., July 1885, p. 347, and which 
had lain in the museum at Oxford since that date. .The specimens and notes 
were given tome unconditionally, but it is convenient to ascribe two of the 
cases to Huxley and the other one to Kent, although I must be held 
responsible for the description of the histological findings and the inter- 
pretations based thereupon. | 
A grant from the Moray fund has enabled me to provide the 
illustrations without which the description would lose much of its 
point. ; 
The cases are described in such order that the first most nearly 
approaches the typical female, and the last the typical male, in respect 
of both primary and secondary sexual characters. 
