496 SLONAKER. 



Fig. 37. Pigeon (Columba livia domestica). Adult. Hori2ontal section 

 through center of the fovea of right eye. Section i8|U thick. X 32.3. 



Fig. 38. Pigeon. Horizontal section through center of fovea of right eye. 

 Section 2i,\i. thick. X 32.3. 



Fig. 39. Surf Duck (Oidema deglandi). Horizontal section through center 

 of the fovea of left eye. Eye about three YlovlX^ post mortem. Section 30/4 thick. 

 X 32-3- 



