312 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1948 
(b) 
1mm. 
(d) 
1 mm. 
Ficure 5.—a, central fovea of Aquila chrysaetus. (After Polyak.) 6, central fovea of kingfisher. 
_ (After Kolmer; no scale given by author.) c¢, temporal fovea of Aquila. d, fovea of man. 
