The Sense of Hearing 75 



to the sound of the whistle. Cyon's statement that in order 

 to evoke a response the whistle must be held above the head 

 of the dancer suggests at once the possibility that currents of 

 air or odors instead of sounds may have been responsible for 

 the reactions which he observed. The work of this investi- 

 gator justifies caution in the acceptance of his statements. 

 Neither the conditions under which the auditory tests were 

 made nor the condition of the animals is described with suffi- 

 cient accuracy to make possible the comparison of Cyon's 

 work with that of other investigators. As will appear later, 

 it is of the utmost importance that the influence of other 

 stimuli than sound be avoided during the tests and that the 

 age of the mouse be known. The conclusion reached by 

 Cyon is that some dancers are able to hear sounds of about 

 the pitch of their own cries. 



The fact, emphasized by Cyon, that the mice respond to 

 tones of about the pitch of their own voice is of peculiar 

 interest in its relation to the additional statements made by 

 the same author to the effect that the female dancer is more 

 sensitive to sounds than the male, and that the males either 

 do not possess a voice or are much less sensitive to disagree- 

 able stimuli than the females. In the case of the dancers 

 which he first studied (9 p. 218), Cyon observed that certain 

 strong stimuli evoked pain cries; but later in his investiga- 

 tion he noticed that four individuals, all of which were males, 

 never responded thus to disagreeable stimulation (n p. 431). 

 He asks, therefore, does this mean that the males lack a 

 voice or that they are less sensitive than the females? The 

 fact that he did not succeed in getting a definite answer to 

 this simple question is indicative of the character of Cyon's 

 work. My dancers have provided me with ample evidence 

 concerning the matter. Both the males and the females, 

 among the dancers which I have studied, possess a voice. 



