File:The fundus oculi of birds, especially as viewed by the ophthalmoscope; a study in the comparative anatomy and physiology (1917) (14568967078).jpg

Identifier: fundusoculiofbir00wood (find matches)
Title: The fundus oculi of birds, especially as viewed by the ophthalmoscope; a study in the comparative anatomy and physiology
Year: 1917 (1910s)
Authors: Wood, Casey A. (Casey Albert), 1856-1942
Subjects: Eye Birds -- Anatomy Ophtalmoscope and ophtalmoscopy
Publisher: Chicago, The Lakeside Press
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

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is. The area centralis presents a thick portionof the retina, where the arrangement of theelements recalls that observed at the levelof the yellow spot of the human retina.There is in this region an increase of gan-glionic cells and of the receiving or percipientelements — the cones and rods. The depth of the fovea? may be regarded as ameasure of the sharpness of vision. Slonakerclassifies fovea? as deep, medium and shallow.The round fovea is especially deep inswift Fliers and Birds of Prey; medium toweak in most other birds, except that it isshallow in the domestic Pigeon, and prob-ably lacking in the Hen. Krause is probably right in believing thatdomestication brings about the disappear-ance of the fovea. Both fovese in the bimacular fundi of diur-nal Birds of Prey are structurally much alike,in that they have in them only cones, and onlythose with yellow droplets. Besides this central area (with a fovea)there is often, in Birds, a ribbon- or band-like 20 THE FUNDUS OCULI OF BIRDS
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