52 RESPONSE IN THE LIVING AND NON-LIVING 



threat. When the stimulus is carried beyond moderate 

 limits, the response, owing to fatigue or other causes, 

 may sometimes undergo an actual diminution. 



1-2 !* 1-6 1-6 2-0 2-2 2-* 2-6 2-8 3-0 3-2 3-* 3'6 3-6 4.-0 



FIG. 30. CURVES SHOWING THE KELATION BETWEEN THE INTENSITY OF 

 STIMULUS AND EESPONSE 



Abscissae indicate increasing intensity of stimulus. Ordinates indicate magni- 

 tude of response. (Waller.) 



I have obtained very interesting results, with 

 reference to the relation between stimulus and response, 

 when experimenting with plants. 

 These results are suggestive of 

 various types of response met 

 with in animal tissues. 



1. In order to obtain the 

 simplest type of effects, not com- 

 Fm 31 plicated by secondary phenomena, 



Taps of increasing strength OU6 liaS tO choOS6 Specimens which 

 1:2:3:4 producing in- . . 



Ceased response in leaf- exhl bit little iatlgU6. Having prO- 



cured these, I undertook two series 



of experiments. In the first (A) the stimulus was applied 

 by means of the spring-tapper, and in the second () by 

 torsional vibration. 



