CARINATjE 



Columbiformes 



Wonga Wonga Dove. Leucosarcia picatct. Plate IX. 



The ocular background is of a uniformly gray tint. White dots, 

 lighting up the fundus, are scattered over the entire field. A few 

 choroidal vessels are to be seen. 



The optic disc forms a long oval; it appears as if it were com- 

 posed of a collection of white fibres, and these seem bunched together 

 for about one-half the length of the pecten. Opaque nerve fibres 

 radiate from the circumference of the papilla, while several orange- 

 red (choroidal) capillaries, interspersed with pigment dots, run on 

 either side of it. 



The pecten appears as an exceptionally long, corrugated, dark- 

 brown mass. Seen through the mirror from above it has the appear- 

 ance of a piece of tarred rope. The single macular area is seen to the 

 inner side of the disc and a little above its upper end. The sheen of 

 the pale green reflex that plays about it when illuminated by the 

 light of the ophthalmoscope looks like watered silk. The fovea has 

 the appearance of a small green flare, something like that from a 

 bull's eye lantern seen close at hand. 



European Wood Pigeon. Columba palumbus. Plate X. 



The tint of the ocular background is pale slate-gray. The eye- 

 ground is covered with very small, dull-white dots, so that the whole 

 fundus presents a lighter shade of gray than it otherwise would. On 

 the lower half and each side of the optic disc are seen several orange 

 colored choroidal vessels, which become more numerous as one 

 approaches the periphery. Extending at right angles to the papil- 

 lary margin are a few opaque nerve fibres. 



A little above the superior end of the optic nerve head and 

 towards the nasal side, is a small, round, apparently somewhat de- 

 pressed macular area of a dull-gray tone. From its margins run 

 a double row of fine, blue-green, translucent lines which form about it 

 a broken or irregular reflex ring. The bird becomes unusually rest- 

 less when the light from the ophthalmoscopic mirror is focused on 

 this part of the fundus. The optic disc appears of a dead white 

 color, and seems to have a fringe of short fibres of the same color all 

 about its edges. At the junction of the pecten with the nerve-head, 

 i. e., along the central area of the latter, one sees numerous brown 

 pigment dots that appear like small rootlets or capillaries and give 

 a reticulate appearance to the papilla. 



The pecten itself has a dark chocolate-brown color and a cork- 

 screw contour; it is unusually long and narrow, and its lower seg- 

 ment appears to come well forward towards the lens. 



128 



