162 RESPONSE. IN .THE LIVING AND NON-LIVING 
course of the experiment, the deflection in each curve’ 
was measured from a line joing the beginning of the 
response to the end of itsrecovery. A mean deflection, 
corresponding to each intensity, was obtained by taking 
the average of the descending and ascending readings. 
The two sets of readings did not, however, vary to any 
marked extent. 
The deflections corresponding to the intensities 1, 
3, D, 7, are, then, as 9°5 to 18, to 30, to SiS siiee 
deflections had been strictly proportionate to the inten- 
Response 

° s lountts. ° 5 1Ountts. 
Stimulus 
Fic. 104.—Curves GiIvinc THE RELATION BETWEEN INTENSITY oF LIGHT AND 
MAGNITUDE OF RESPONSE 
In (a) sensitive cell, (b) in frog’s retina, 
sities of light stimulus they would have been as 9°5 to 
28°5, to 47°5, to 66°95. 
In another set of records, with a different cell, 
I obtained the deflections of 6, 10, 13, 15, corresponding 
to light intensities of 3, 5, 7, and 9. 
The two curves in fig. 104, giving the relation 
between response and stimulus, show that in the case of 
inorganic substances, as in the retina (Waller), magnitude 
of response does not increase so rapidly as stimulus. 
After-oscillation—When the sensitive surface is 
subjected to the continued action of heht, the E.M. 
