56 MAN AN ADAPTIVE MECHANISM 



repetitions of the stimulation ; the lowering of response 

 by depressants; and the abolition of response by 

 poisons. In our own laboratory we have by experi- 

 ment shown that the energy of Venus' fly-trap, like 

 that of man, can be exhausted by repeated stimulation ; 

 that, as in man, its energy may be restored by rest ; 

 and that it may be anesthetized by the agents used in 

 anesthetizing man. 



' In the three separate stages of adequate stimulus, 

 conduction and end effect which compose the reaction 

 of Venus' fly-trap, we find all the essential factors 

 which enter into the life activities of man. Under 

 adequate stimulus, for instance, are included the ac- 

 tivating stimuli produced by heat and cold, dust, 

 debris, microorganisms, food, air, water, light, poisons, 

 blows, by certain physical and chemical changes 

 within and without the body, to which man through 

 evolution has become " adapted " through the creation 

 of an adaptive response. Conduction is supplied by the 

 central and autonomic nervous systems, that is, by the 

 organs of touch, taste, sight, smell, hearing, pain 

 and by the chemical receptors for the initiation of cer- 

 tain reactions of chemical control. End effects are 

 found in all the vital processes of motion and emotion, 

 muscular activity, chemical change, psychic states, 

 growth, nutrition, reproduction, thought, invention, 

 social forms, government, war, religion, business, - 

 in short, in all the activities by which man's life is 

 distinguished from the immobility of the rock. In 

 other words, magnification of the typical motor and 

 chemical response of the sensitive plant gives us a 

 concrete illustration of the premise stated above, that 



