QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by DAWES, B. Search for Related Content PubMed Articles by DAWES, B.

Journal of Experimental Biology 18,99-109 (1941)
Published by Company of Biologists 1941

Notes on the Distribution of Pigment Granules in the Retinal Pigment Epithelium of Light- and Dark-Adapted Rana Temporaria, and on the Nature of the Eye Pigment in the Frog and the Ox

BEN DAWES D.Sc.¹

¹ Department of Zoology, King's College, University of London

The retines of twenty-two adult Rana temporaria were examined following varied experimental treatment. The disposition of pigment granules in the pigment epithelium canot invariably be explained in terms of migration. Individuals which were subjected to the radiations from a mercury-vapour lamp showed dense aggregates of pigment granules in both the bodies and the processes of the pigment cells. The possible significance of this observation is discussed.

The amount of pigment in the epithelium does not appear to very in accordance with the amount of melanin contained in the skin. The amount of pigment appears to be greater, however, in pigment cells near the rim of the retina than in cells at the fundus of the retina. Hypophysectomy of 4 or 5 weeks' standing is without effect on the amount of pigment present in the pigment epithelium or on the disposition of granules in light- and dark-adapted retinas. Subcutaneous injection of post-pituitary extract is likewise without effect on the disposition of granules under conditions of both light and darkness.

Pigments extracted from the choroid and retina of the frog and the ox have been compared with one another and with the pigment extracted from the digested skin of the frog. Spectrophotometric data indicated no essential difference between these pigments.