6 COLOR SENSITIVITY OF THE PERIPHERAL RETINA. 



able contribution to the solution of the problem ; and one is encouraged 

 to grapple with it anew by a recognition of the value of this heritage 

 from the past a heritage which consists not only in an intimate knowl- 

 edge of many of the facts of vision, but also in an extraordinary refine- 

 ment of apparatus and of method. In entering into possession of this 

 inheritance it seems distinctly worth while to go over the ground and 

 discover its extent and value. We shall therefore preface the report of 

 our own experiments with a detailed history of the problem-; and, in 

 the light of the accrued advantages of the present generation, we shall 

 attempt to evaluate the results of previous investigations. 



Our paper represents the work of the past year. The leisure re- 

 quired for a year's concentration upon this topic was rendered possible 

 by a grant from the Carnegie Institution of Washington. The writer 

 takes this opportunity to express his gratitude to the members of the 

 Institution for their assistance in his undertaking. 



The experiments upon which this paper is based will be described 

 in detail in a later section.* The experimenter was in consultation 

 throughout with Professor E. B. Titchener and Assistant Professor 

 I. M. Bentley, to both of whom he is indebted for advice and criticism. 

 He is also under obligation to Professor L/ightner Witmer, of the Uni- 

 versity of Pennsylvania ; to Mr. L/ouis Wilson, of Clark University ; to 

 Mr. Willard Austen, of the library of Cornell University ; and to Major 

 Walter D. McCaw, of the Surgeon-General's library at Washington, 

 D. C., for aid in obtaining access to the literature of his subject. 



*See pp. 42ft. 



