405 



during class-work. As the ligure shows, the right lobe of the bladder 

 is quite normal, but the left lobe has, in some manner not easy to un- 

 derstand, become proximally stretched to form a thin tube which, 

 running anteriorly in the body-cavity, perforates the muscular portion 

 of the ventral body-wall and swells distally into a spherical sac lying, 

 in consequence, externally to the muscles and in the median ventral 

 lymph-sinus. Inhabiting this distal sac and, owing to the small size 

 of the aperture made in the body-wall by the protruding bladder, per- 

 manently imprisoned therein, was found a full-grown specimen of the 

 trematode so often found in the bladder of the frog [Pühjstomum 

 integerrimum). In no part of the animal were any signs of disease ob- 

 servable other than those just mentioned. 



A, distal sac of left bladder-lobe lying to the exterior of the muscular portion of the 

 bodj'-wall in the ventral lymph-sinus; B, the imprisoned trematode; C, the stretched 

 proximal portion of the left ])ladder-lobe lying in the body-cavity; Z>, the muscular 

 portion of the body-wall ; £', Post-caval vein; i^, Kidney; 0, Testis; H, Rectum 



J, right lobe of bladder. 



The only feasible interpretation of this abnormal condition of the 

 bladder which suggests itself is that the protrusion of the left lobe 

 through the body-wall is an embryonic freak and that the young tre- 

 matode migrated, when still of small size, to the distal external portion 

 of the bladder-lobe in which it grew to its present dimensions. 



Biological Department, London Hospital Medical College. 



