PLATE 3 



EXPLANATION OF FIGURES 



9 Microphotograph of bladder prior to experiment. The characteristic 

 arrangement of the smooth muscle and the transitional epithelium are clearly 

 seen. X 42 



10 Microphotograph of same bladder forty-eight days after experimentation. 

 The bladder was subjected to 200 times more work than it normally experiences. 

 The smooth muscle was transformed into striated muscle in response to 

 increased hydrodynamic tensional stimuli. The transitional epithelium hyper- 

 trophied into the stratified squamous type. X 42 B. & L. objective 16 mm. 

 ocular 5. 



11 Microphotograph of smooth muscle of the bladder prior to the experi- 

 ment March 30, 1921. No cross-striated muscle is seen. X 171 



12 Microphotograph of the transformed cross-striated bladder muscle May 

 21, 1921. X171. B. & L. Obj. 4 mm. 0.85 ocular 5. 



13 Microphotograph of cardiac muscle. X 84. 



368 



