330 The Effects of Ultra- Violet Rays upon, the Eye. 



Plate 5. — Absorption Spectra of Media of Eye (Ultra-violet Region). 



A. Iron arc ; 2 sees. 



B. Cornea ; 5 sees. 



C. Lens ; 3 sees. ; thin film in quartz cell. 



D. Lens ; 1 sec. ; film 1/16 inch thick. 



E. Lens ; 5 sees. ; film 2/16 inch thick. 



F. Lens ; 60 sees. ; suspended in saline. 



G. Vitreous ; 30 sees. ; 3/16 inch thick. 



H. Vitreous ; 3 sees. ; 3/16 inch thick. 



Plate 6. 



Rabbit No. 3. Anterior lens capsule of normal unexposed eye. The number of mitoses 

 present is indicated in the key above by dots ; the position of the fields drawn is 

 indicated by circles. (Zeiss D, Oc. 4.) 



Plate 7. 



Rabbit No. 3. Anterior lens capsule of exposed eye. The dots in the key represent the 

 distribution, not the number, of mitoses. The left field shows normal cells under 

 cover of the iris ; the central field shows dividing nuclei at the pupillary margin ; 

 the right field shows the greater cell-proliferation where the stimulus is of maximal 

 intensity. (Zeiss D, Oc. 4.) 



