Vid.-Selsk. Skr. I. M.-X. Kl. 1922. Xo. 4. 



PI. MI. 



■œ^^iî.'.l;?"/ :,.^^S: A^n- f'-yS^- -vJfc t** 





Fig. 16. A section, so oblique as to be almost a surface-section, through 

 a place in the iris where the dilatator has developed. It will be seen that 

 the myoglia fibres show a tendency to run out into points. The nuclei are oval 

 and short as the\^ are usuallv stated to be in the dilatator. Defective 

 depigmentation. Stained by Heidenhain's method, x looo. 



Fig. 17. A photograph gi\-ing a general idea of the relation of the tube-like processes formed 



by duplicature of the epithelium, to the sphincter, a. The duplicature of the epithelium, 



undepigmentated. b. The back layer of the epithelium, x about 200. 



