Discrimination of Light of Different Wave-Lengths by Fish (Volume 19) (Paperback)

This historic book may have numerous typos or missing text. Not indexed. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. 1919. Not illustrated. Excerpt: ... DISCRIMINATION OF LIGHT BY FISH I. STATEMENT OF THE PROBLEM In the early part of the second half of the nineteenth century many comparative studies of the anatomy of the eye were made. Studies of the physiology of the human eye followed, but experimental work upon animal vision was delayed. Not until 1885 were Graber's results published. He was among the first to test experimentally the effects of light of different wave-lengths upon fish, and found that they showed a preference for the shorter wavelengths. Then a number of other experimenters decided that fish discriminate color. But in 1909 and 1910 Hess published an account of experiments from which he concluded that fish do not show the responses to wave-length apparently established by his predecessors in this field. He attributed the responses obtained by him as well as those already obtained by others to differences in the brightness rather than to differences in the quality of the light used and held that fish are color-blind. His evidence has been given favorable consideration by a number of investigators of color vision in higher vertebrates (Watson 1914, Parsons 1915). From this discussion arose the definite problem, --to determine whether fish can respond to differences in wave-length of light or can respond only to differences in intensity8 of light. II. EXPERIMENTAL WORK A. Introduction.--The first requirement for the solution of the question was to determine whether our native fish show responses' available for experimentation. For some 1 Contribution from the Zoological Laboratory, University of Michigan 2 In this paper intensity is used as a physical term, and brightness as a sensation term; quality is used to describe that phase of sensation dependent upon wavelengths. 3 The study of first...