Open AccessThe absorption of light by the coloured globules in the retina of the domestic hen
Author(s) -
H. E. Roaf
Publication year - 1929
Publication title -
proceedings of the royal society of london. series b, containing papers of a biological character
Language(s) - English
Resource type - Journals
eISSN - 2053-9185
pISSN - 0950-1193
DOI - 10.1098/rspb.1929.0049
Subject(s) - visibility , visible spectrum , absorption (acoustics) , retinal , optics , biology , chemistry , physics , botany
Schultze (1866) pointed out that the coloured globules in the retinæ of birds might afford a means wherby stimulation of the cones would be restricted to certain regions of the visible spectrum (7). A few other investigators have ascribed sensual discrimination of colour to retinal filters situate in front of the specific receptors fro light (1, 4 and 6). An alternative view (2, 3) regards the coloured globules as decreasing, merely generally and relatively unselectively,i. e. , quantitatively rather than qualitatively, the amount of light of short wave-length which reaches the sensitive (outer) limb of the cones. This might possibly be useful by reducing the amount of the more highly scattered light and so might improve the visibility of distant objects (2). This, however, can hardly be the full explanation, for if the function of the coloured globules be merely to reduce the amount of the more refrangible end of the spectrum the various globules need not be of more than one colour.