Abstract
SOME animals, such as the earthworrn, have no eyes, and yet they are photoropic either in a positive or negative sens according as tney move towards or away from light. Others, such as planarians, have be markably simple eyes, consisting of one or several sense elements, behind which is a pigmented up, composed of one or more cells. Such eyes cannot form an image, and they have been Called “direction eyes” because light from only one direction can affect such an eye at a given time. Higher in the scale we find the “compound” or “mosaic” eye, as in injects and other animals. The question arises, To what extent is an image or images formed by such an eye composed of many ocelli? There can be no doubt that the compound eye forms an image or images. Exner has taken a photograph through the eye of a fire-fly, and Parker has shown that the compound eyes of Astacus form a single image. Lastly, we find in vertebrates the “simple” eye, the optical construction of which leads to the formation of art image on the retina. The image of a distant object can readily be seen on the retina of a fresh eye removed after death from an albino rabbit, and if a lighted candle be placed in front of the isolated eye of a frog, a beautiful little inverted image of the flame may be visible on the sclerotic.
Article PDF
Rights and permissions
About this article
Cite this article
MCKENDRICK, J. Have All Eyes the Power of Forming Images? . Nature 76, 274–276 (1907). https://doi.org/10.1038/076274a0
Issue Date:
DOI: https://doi.org/10.1038/076274a0