I'.] 



PERIOD OF HESITATION 



33 



possible with very gradual compression to obtain response of 

 the transitional type. 



The conversion of type I. into type III. by means of gentle 

 massage forms a simple and almost an unfailing lecture demon- 

 stration. Fig. 14 is the record of a case in point. 



17. A double process. I think that any one who has wit- 

 nessed a great number of experiments of this character, and 

 who has carefully inspected a large number of records such as 

 those figured above, will be forced to the conclusion that the 

 normal positive response is the algebraic sum of two opposite 



FlG. 16. Frog's eyeball. False latent period or period of hesitation 

 in this instance = 5 sees. 



and almost synchronous electromotive phenomena, one giving 

 a positive current that over-compensates the other giving 

 negative current ; the first more labile than the second, so that 

 by gentle compression it may, so to say, be wiped out, and 

 the second be thus unmasked. 



A careful scrutiny of the manner in which the normal positive 

 response begins and ends confirms this view, and at the same 

 time offers to us a plausible explanation of what has been referred 



C 



