PRELIMINARIES TO A STUDY OF COLOR VISION 

 IN THE RING-DOVE TURTUR RISORIUS^ 



ROBERT M. YERKES 



Assisted by A. M. EISENBERG 



From the Harvard Psychological Laboratory 



At the present moment a thorough study of the visual reac- 

 tions of a few types of birds and mammals is highly desirable. 

 This paper presents an account of observations on the reactions 

 of the ring-dove in the Watson- Yerkes color vision apparatus. 

 The ring-dove was chosen as a subject because of its easy adap- 

 tation to laboratory conditions and its convenient size. It was 

 hoped that it might prove an ideal bird for the intensive study 

 of vision. 



As a preparation for the study of color discrimination, the 

 limits of the spectrum, and the stimulating values of various 

 waye-lengths, observations were first made on the response of 

 the bird to achromatic stimuli. The apparatus used throughout 

 the preliminary work here reported was the Watson- Yerkes 

 spectral color vision device, as described in volume one of the 

 Behavior Monographs. 2 A Bausch and Lomb automatic arc 

 lamp was used as a source of light, and a selenium cell, as de- 

 scribed in the monograph (pp. 79-81) served as a means of 

 measuring the energy of the stimuli employed. For the simple 

 reaction-box shown as W in figure 7 of the monograph, the 

 box represented in figure 1 of this paper was substituted, and 

 instead of having two reflecting surfaces, M and L of figure 7 

 above referred to, fixed on the experiment-box and moving 

 laterally with it, three reflecting surfaces were employed. These 

 remained fixed while the experiment-box moved sufficiently to 

 reverse the position of the two photic stimuli. 



1 This work has been made possible by a grant from the Bache Fund of the 

 National Academy of Arts and Sciences, which enabled the author to complete 

 the construction of a spectral apparatus and install a selenium cell outfit to 

 measure chromatic stimuli. Grateful acknowledgment is made to the trustees 

 of the Fund and to the Committee in charge, for the facilitation of this research. 



2 Yerkes, Robert M., and Watson, John B. Methods of studying vision in 

 animals. Behavior Monographs, 1911, vol. 1. 



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