THE FUNDUS APPEARANCES IN VARIOUS ORDERS OF BIRDS 



111 



About three disc-breadths from the upper 

 end of the disc on the inner side is a well 

 marked, bright reflex of a greenish-blue 

 tinge. It is irregularly oval in shape and 

 seems to be composed of a number of very 

 fine fibres. In the center of the reflex is the 

 macula, a small, dark, crater-like depression, 

 brown in color. The disc is chalky white, 

 and gives one the impression that it is com- 

 posed of many opaque nerve fibres packed 

 closely together. From the disc margins 

 there radiate a number of fine optic nerve 

 fibres that extend across the eyeground. In 



the lower part of the fundus, associated with 

 a number of orange-red dots, are a few orange- 

 red choroidal blood-vessels, several of the 

 latter being distributed along either side of 

 the disc. 



The pectens in all the Ravens examined 

 were of similar shape and of the usual dark- 

 brown color. They were very thin and nar- 

 row at the disc but assumed a club-shape as 

 they approached the lens where they were 

 darker in color. The pecten comes well 

 forward and appears at times to press against 

 the posterior capsule of the lens. 





