RATITvE 



Struthioniformes 



Nubian Ostrich. Struthio camelus. Plate I. 



The general color of the eyeground is dull red, besprinkled with 

 lighter-red, round dots and gray granules. The lower half of the 

 fundus appears somewhat grayer in tone than the upper sectors. 

 This appearance is probably due to the numerous opaque nerve- 

 fibres that extend from all sides of the papilla as a centre across the 

 fundus to the periphery of the ocular background. The red colora- 

 tion of the fundus is seen to be more intense towards the upper half 

 of the eyeground. The optic nerve entrance is very broad and oval 

 in shape. The margins of the nerve head are very white and it is 

 possible with the mirror to see all around the pecten. The centre of 

 the disc, including the parts near the root of the pecten, are stippled 

 with minute brown pigment dots, like black pepper grains. The 

 pecten presents the appearance of a number of dull, dark, sepia- 

 brown tubercles. It does not project far forward into the vitreous 

 cavity, while its outlines and contour may be distinguished both 

 above and below the disc. The pectinate margins are formed of 

 round, ovoid projections. The macula is not very striking in appear- 

 ance, and takes the form of a crescentic arrangement of minute, 

 gray dots. It is seen towards the nasal side of the disc near its 

 upper end. 



Rheiformes 

 American Ostrich. Rhea americana. Plate II. 



The coloration of the fundus as a whole is buff, merging into dull 

 red at the periphery. It is stippled all over with minute dots of a 

 lighter tint. 



The optic disc is made up of white and coarse nerve bundles that 

 exhibit a faintly defined, fringe-like border all around its margins. 

 Radiating for a distance of about two disc-breadths across the fundus 

 are a few, dull-gray, opaque nerve fibres that finally disappear into the 

 background. 



The macula is situated slightly above and to the nasal side of 

 the optic papilla. It is somewhat grayer than the surrounding 

 eyeground; above (towards the outer side) and below the fovea are 

 a, few pale, bright green reflex lines. 



The pecten is a massive organ with saw-like margins, the serra- 

 tions being of a lighter brown than the central body. The lower part 

 of the pecten is somewhat club-shaped, and comes well forward 

 toward the posterior capsule of the lens. Between the projecting 

 teeth of the pectinate serrations may be seen a slight stippling of 

 pigment-like black pepper grains. 



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