Image formation is studied in compound eyes of insects that contain crystalline tracts. In optical experiments the course of light is studied in fresh scalps of dark-adapted eyes using point and extended sources. In the tract region a point source gives a diffusely lighted area within which are punctate spots about 10 times brighter. Because the position of these spots does not change when the source is moved, and because their spacing agrees with estimates based on the known scalp depth, we conclude that these spots represent light radiating from the cut ends of tracts. An extended source gives a dim erect image in the tract region that may come from the pattern of illumination radiating from the cut ends of the tracts. In electrophysiological experiments intracellular microelectrode recordings of responses to illumination are made from single retinular cells of the skipper, Epargyreus clarus, an animal that lacks iris pigment. Measurements of visual fields of single retinular cells by three methods give half-power beam widths of about 2°. Though not conclusive, these experiments suggest that only the light contained in the tract is effective in stimulating the retinular cell. This agrees with the theoretical study of Allen (1968) and is inconsistent with the superposition theory of Exner (1891) as applied to certain moth and skipper eyes.
Article|
August 01 1969
Function of Insect Compound Eyes Containing Crystalline Tracts
Kjell B. Døving
,
Kjell B. Døving
From the Section of Ophthalmology, Yale University School of Medicine, New Haven, Connecticut 06510.
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William H. Miller
William H. Miller
From the Section of Ophthalmology, Yale University School of Medicine, New Haven, Connecticut 06510.
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Kjell B. Døving
From the Section of Ophthalmology, Yale University School of Medicine, New Haven, Connecticut 06510.
William H. Miller
From the Section of Ophthalmology, Yale University School of Medicine, New Haven, Connecticut 06510.
Dr. Døving's present address is Institute of Zoophysiology, University of Oslo, Blindern, Oslo, Norway
Received:
March 10 1969
Online Issn: 1540-7748
Print Issn: 0022-1295
Copyright © 1969 by The Rockefeller University Press
1969
J Gen Physiol (1969) 54 (2): 250–267.
Article history
Received:
March 10 1969
Citation
Kjell B. Døving, William H. Miller; Function of Insect Compound Eyes Containing Crystalline Tracts . J Gen Physiol 1 August 1969; 54 (2): 250–267. doi: https://doi.org/10.1085/jgp.54.2.250
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