1904.] of the Gall Bladder of the Frog. 431 



I am indebted to Dr. Alcock for sections of the gall bladder of the 

 frog and cat which he kindly prepared for me, and to Mr. Gordon 

 Webb for enlarged micro-photographs of the same. The gall bladder of 



FIG. 2. 



Photograph of Electrometer Record of the Blaze Currents of G-ali Bladder. 

 Deviation of y (1 volt. 



Coil at 5000 + = -0-0060 volt. 



the frog consists of a single layer of columnar nucleated cells, and 

 layers of smooth muscle fibres with connective tissue. The bladder of 

 the frog is quite round and the layer of columnar cells lies flat, 

 whereas in the cat the bladder is a long-shaped body with the layer 

 of columnar cells thrown into folds, and outside the smooth muscle 



FIG. 3. 



Section of Frog's Gall Bladder, showing Inner Mucous Layer of Columnar 

 Epithelium, and Outer Layers of Smooth Muscle Fibres. (Enlarged 

 2500 diameters and Photographed by Mr. H. Gordon Webb, Assistant 

 Demonstrator of Anatomy in St. George's Hospital Medical School.) 



