Instinct and Memory 27 



plasm of elements possessing the basis of 

 memory and inheritance. For example, Stentor, 

 although its body-substance and nucleus are 

 structurally of greater complexity than those of 

 Amoeba, is nevertheless a unicellular being. 

 The movements effected by the protoplasm of 

 this animal have been carefully studied by Asa 

 A. Schaeffer; he gives in detail a clear account 

 of his experimental work, and arrives at the 

 following conclusions : l 



1. Stentor caeruleus excises a selection 

 among particles that are brought to its food- 

 pouch; certain particles are rejected, others are 

 carried to the mouth and ingested ; in selecting 

 food it probably reacts to physical properties 

 only or chiefly, and not to chemical properties. 



2. Stentor discriminates very accurately be- 

 tween organisms and indigestible particles, the 

 latter of many sorts which have for thousands 

 of generations not come in contact with Stentor 

 are nevertheless rejected. 



1 fhe Journal of Experimental Zoology, Vol. VIII., No. i, 

 January, 1910, pp. 894-5. 



Prof. A. J. Ewart *"emarks, when referring to the movements of 

 organisms possessing locomotory organs, that they have "acquired 

 the power of directing and controlling the natural forces to their 

 own benefit." Physics and Physiology of Protoplasmic Straining 

 in Plants, p i '2. 



