PHYSICAL IMITATIONS OF THE ACTIVITIES OF 

 AMCEBA. 



Physical imitations of the activities of lower organisms, such 

 as are given us by Butschli and Rhumbler, have always taken 

 a place among the " startling achievements " of science. They 

 arouse a lively interest in the popular mind as well as in the 

 minds of men who are seriously studying the problems which 

 such activities present. Anything which promises a bridge 

 from the inorganic to the organic, from the physical to the vital, 

 demands attention. Almost all men have definite convictions 

 as to the relation of these two fields, — convictions which are 

 foundational for the whole superstructure of intellectual or 

 religious life ; anything which touches these convictions must 



How far have the physical imitations of vital activities gone ? 

 What do they really show as to relation of physical and vital ? 

 In the present paper such physical imitations as relate to one 

 of the lowest organisms. Amoeba, will be examined with these 

 questions in view. The greater number of the physical experi- 

 ments relate directly to Amoeba, attempting to imitate its 

 behavior. The writer has recently made a thorough re-examina- 

 tion of the behavior of this animal, the results of which have 

 been published elsewhere (Jennings, : 04), so that opportunity 

 is presented for a comparison between the imitations and the 

 reality. By determining to what extent the physical imitations 

 throw light on the behavior of Amoeba, we shall perhaps have 

 a fair measure of what has been accomplished in this way, and 

 of the promise for the future. 



What is the real purpose of the physical imitations of vital 

 activities ? Clearly, the final purpose is to show what physical 

 factors are at work in these activities. But this end may be 

 followed in many ways ; what is the special purpose of the 



