18 
the time and labor spent upon it, and that side lights may, in this 
way, be thrown upon some of the problems (as yet unsolved) of 
human ophthalmology. 
The following description of a few of these fundi will serve to 
show the variations in avian backgrounds, and is published as a note 
preliminary to further investigation of the subject. 
THE EATITiE. 
The ocular fundus of the Kiwi or Apteryx Mantelli. (Plate II.) 
This is the only background of the sub-class Katitae, or birds with 
functionless wings that I have to exhibit. It is one of the oddest of 
the Australian birds—something like a thin little Cassowary with 
thick legs, no visible wings, and a long bill like a snipe. The nostrils 
are placed at the very tip of this slender beak, which the bird deeply 
plunges into the soft ground, smelling about for worms, which, when 
discovered, are drawn out and eaten. Kiwis are nocturnal in their 
habits and for that reason are rarely seen by visitors to our zoological 
parks and gardens. If aroused from their straw during the day¬ 
time they open their mouths several times in long-drawn and very 
human yawns and then fall asleep again. 
The fundus of the Apteryx, in comparison with that of most 
carinate birds, suggests its nocturnal life. Indeed, all animals that 
prowl, run about or feed at nighttime have brilliant yellow, orange 
or yellow red fundi. 
The almost uniform red, mottled background of the Apteryx, 
shows no blood vessels in his retina whatever. The chorioidal pig¬ 
ment is less plainly seen in a concentric area surrounding the re¬ 
markable optic nerve entrance. Here the brilliant, white, round 
disk surrounded by short, opaque nerve-fiber rays is not entirely 
covered by the fenestrated base of the long^ large and regularly con¬ 
ical pecten which reaches almost to the lens. If one were allowed to 
stretch his imagination, the combined picture of pecten and nerve- 
head might be said to resemble a black rubber teat from a nursing 
bottle, partly stretched over a white sea-urchin. How the Kiwi's 
pecten could have remained undiscovered for so many years is diffi¬ 
cult to explain, except that it emphasizes the difficulties in the way 
of a satisfactory exploration of birds' fundi in general and the differ¬ 
ences between the erect, vascular, functionating pecten of the live 
