80 RESPONSE IN THE LIVING AND NON-LIVING 
effect of very dilute KOH, and fig. 49 exhibits nearly 
complete abolition of response by the action of the same 
reagent when given in stronger doses. 
So we see that, judged by the final criterion of the 
effect produced by anesthetics and poisons, the plant 
response fulfils the test of vital phenomenon. In 
previous chapters we have found that in the matter 
of response by negative variation, of the presence or 
absence of fatigue, of the relation between stimulus and 
response, of modification of response by high and low 
temperatures, and even in the matter of occasional 
abnormal variations such as positive response in a 
modified tissue, they were strictly correspondent to 
similar phenomena in animal tissues. The remaining 
test, of the influence of chemical reagents, having now 
been applied, a complete parallelism may be held to 
have been established between plant response on the 
one hand, and that of animal tissue on the other. 
