23 
'white, narrow oval, with a number of fine gray lines (opaque nerve 
libers) radiating from its margin and extending toward the macula, 
d he foveal region is an oval, reddish-brown area, surrounded by a 
gray-blue, iridescent reflex. The pectcn seems to be in folds (about 
eight), the lower or broader portion extending toward the nasal half 
of the eyeball. 
The Blade Ilornbill (Sphagolobus Alratus). —This curious mem¬ 
ber of the Coccygomorphae has remarkably good sight for such a 
stupid-looking, top-heavy bird. In experimenting with his visual 
powers I found that he caught, with his enormous beak, grapes 
thrown into the air as quickly and as easily as a seal catches fish. 
Like the other hornbills, his lids are furnished with long, well- 
developed lashes. The specimen I examined had been in the Lon¬ 
don Zoo for years and did not present any disease of the fundus, 
although his refraction, determined at night by skiascopy, was about 
emmetropic. The background is of a drab or dull-gray color, and 
the retinal reflex is so marked that it is difficult to recognize the 
minute fundus details. The papilla is, as usual, on the nasal side 
of the eyeground, in the shape of a long, white oval about which 
opaque nerve fibers extend almost to the periphery. Toward the 
equator are seen faint red chorioidal vessels. The pecten is quite 
large and its antero-posterior view shows a saw-like contour (with 
about 20 plications or teeth on each edge), except at its distal ex¬ 
tremity, which is more club-shaped. The pectinate body in this 
bird can readily be seen to expand and contract, apparently with 
the movements of the pupil. The foveal region is a red-brown, disk¬ 
shaped area with a dark-red spot in its center. The retinal reflexes 
are very noticeable, and give the impression of an iridescent, bluish- 
o-reen sheen, so much so that it reminds one of a dull mirror re- 
fleeting colored light thrown upon it. 
In a future paper I hope to furnish a description of a still larger 
series of avian fundi. 
From the foregoing I believe we are justified in drawing the 
following conclusions: 
1. The highest expression of vision, including the most varied 
and widest range of accommodation, is found in bird life. 
2. The owls possess binocular sight, and their eyes in many other 
respects resemble those of man. 
