Abnormalities of Reproductive System found in Frogs. 247 
CASE No. V. 
Rana esculenta. Adult, measuring 8 cm. from the symphysis menti to the 
symphysis pubis. Killed November. 
External characters—External vocal sacs extruded in death.  Fore- 
limbs massive. Finger-pads well defined and lightly pigmented. Skin 
of the back and flanks not warty (Fig. 13). 
On inspection, right gonad had the appearance of an unusually large, 
irregularly shaped testis which bore along its twisted outer border a 
discontinuous band of jet-black pigment which lay in deep uneven grooves. 
The gonad measured 16x10x8 mm., and the pigment at some points was 
piled up into rounded nodules resembling pathological ovarian tissue. At 
the extreme posterior pole of the gonad was a small projecting: spherical 
lobule of spermatic substance, separated from the main-body of the gonad 
by a deep constriction. 
The left gonad, measuring 11x64 mm., had the form of six rounded 
lobules. One of these, whitish in colour, stood out in vivid contrast to the 
others, and was placed upon the inner border of the gonad with the other 
five lobules arranged anteriorly, externally, and posteriorly in relation to it. 
The one was obviously normal testis-substance, while the others, irregularly 
rounded and intensely pigmented, closely resembled abnormal ovarian 
tissue. 
Vasa efferentia on the right side were as those of the ordinary male. 
On the left side there were but four. Seminal vesicles, small and spindle- 
shaped. Miillerian ducts, well developed with uterine segments of moderate 
size. Four openings into the cloaca. 
On section. In the right gonad, all parts save those including pigment 
had the structure of normal testis. The pigmented parts consisted of 
closely-packed polygonal masses of pigment and fibrous tissue only. No 
ova were found amid the pigment, but near to it were found, between the 
seminal tubules, two ova. The pigment was discrete from the seminal 
tubules but the line of junction between them was very irregular, and the 
inspection of single sections gave the impression that this typical ovarian 
tissue was invading the spermatic tissues along the lines of the intertubular 
connective tissue (Fig. 14). The seminal tubules in the neighbourhood of 
the pigment were imperfect in form. Im the figure one of the ova is 
clearly seen to lie between and not within the seminal tubules. 
Left gonad. The five black lobules had the structure of pathological 
ovarian tissue, consisting of polygonal masses of pigment, hyperplastic 
connective tissue, and amid these, a few very degenerate ova, The sixth 
