071 the Retinal Currents of the Frog's Eye. 



327 



mena,"'^ of which we have as yet no sufficient cognizance. They strive 

 to reach the generalisation of a Newton, without the numerical founda- 

 tions laid by a Tycho Brahe and a Kepler. 



On the Eetinal Currents of the Frog's Eye, excited by Light and 

 excited Electrically." By Augustus D. Waller, M.D., 

 F.RS. Keceived and Eead March 29, 1900. 



(Abstract.) 



I. Introduction. 



II. Plan of experiment. 



III. Kesults. 



1. A fresh normal eyeball manifests positive current, which gradually 

 declines to zero, and becomes reversed. 



2. On exposure to light the normal current, whether positive or 

 negative, undergoes a positive variation. 



Fig. 1. 



Norm<xL response 



3. The magnitude of the response to light increases with the dura- 

 tion of illumination. 



Fm. 2. 



* Germ plasma and other theories are invented before we know fully the facts 

 they are supposed to describe. 



