vi Journal of Comparative Neurology. 



of course, necessary that the head movement should be a pure motor 

 reflex with no previous visualization. 



With practically the same head deviation the eyes describe an 

 arc of 9 deg. after one second, 22 deg. after two seconds, 30 deg. af- 

 ter three seconds, and 39 deg. after four seconds. The longer the 

 time the weaker the motor stimulus which tends to turn the closed 

 eyes in the direction of the object. The decrease is quickest where 

 the impression is simple. A card having nine pictures upon it after 

 four seconds has the power to turn the eyes 16 deg. A curious ex- 

 ception is found in the addition of figures in which case the eyes turn 

 nearly as far as the head. This is explained, however, as not due to 

 the inferior motor power of the process but to its being so great as to 

 prevent the head-movement from being made as a reflex. The calcu- 

 lation was so absorbing that the head motion could only be made by 

 interrupting it and giving conscious attention to the effort. I'he au- 

 thors think that the whole question of the psychophysics of attention 

 is by this method opened to an untrammelled and profitable investi- 

 gation. 



c. L. H. 



The Localizatiou of Sound.^ 



The question of auditory localization has always been perplexing 

 and the various theories accounting for it are more or less unsatisfac- 

 tory. Siumpf suggested that localization depends upon a difference 

 of some sort between the sensations of the two ears. Preyer supposes 

 that the semi-circular canals discriminate impressions from different 

 directions. Others think this discrimination is simply an act of judge- 

 ment based on the difference of intensity of sound in the two ears. 



Miinsterberg suggests that the sense of direction depends on a 

 combination of sensation of sound and sensations of movement. 



For the reinvestigation of the facts in the case an ingenious series 

 of experiments was instituted. A horizontal circular zone and arcs 

 of similar curvature which could be adjusted to any position on the 

 horizontal arc, were contrived to carry telephones of equal intensity 

 and quality. 0° mean s in front of the subject, whose head was sup- 

 ported in the centre of the arcs; 9o°r at the right, 180° behind, etc. 

 The answer was always given in degrees by the subject before opening 

 the eyes. 



I. When two symmetrcially placed sounds were heard they were 



^MUENSTERBERG and PlERCE. Psych. Rev., I, 5. 



