332 ASA A. SCHAEFFER 



animars tendencies to move, without the intervention of images" 



(9, P- 249)- 



We have examples in the foregoing observations which give 

 us insight into the frog's method of learning to avoid hairy 

 caterpillars, notably that figured for August g. What took 

 place in the frog's mind when the frog was actively following 

 the caterpillar and closely examining it as it crawled; when 

 the frog lost interest in it until after it had fallen into the water, 

 and began to wriggle in a manner which presumably by its 

 strangeness induced the frog to examine it closely again for a 

 few seconds; and when it finally turned away? Was the frog 

 " defining the construct " of hairy caterpillar, and perhaps also 

 a " reconstruct " of the frog's past experience with it, to use 

 Morgan's terminology, or does the frog's apparent examination 

 of the caterpillar denote a vacillation of the eating and the 

 avoiding habits, both striving, so to speak, to control its behavior? 

 Examination from an objective viewpoint does not necessarily 

 imply subjective processes ; it may be purely or mainly a physio- 

 logic process. The apparent examination of food and other 

 substances by the blue stentor when loops are made by the food 

 particle in its pouch and funnel can hardly be supposed to be a 

 pv'jychic process (8). The elaborate and painstaking examin- 

 ation of empty mollusc shells, and other hollow objects, by a 

 hermit crab, is, according to Brooks, also an instinctive or 

 physiologic process, and little or no intelligence is indicated 

 (2, p. 5). These instances are sufficient to show that the process 

 of examination from a purely objective viewpoint does not of 

 itself require psychic processes to explain it. The two cases 

 can be explained as instinctive examination, similar to the 

 accurately localized scratching movements of the hind legs of a 

 decapitated frog when a drop of acetic acid is placed on the skin. 

 But when examination results in intelligent choice on the basis 

 of very few new experiences, such as has been seen in the be- 

 havior of Rana clamata (medium), the process of examining is 

 probably of a psychic nature, for the known processes of ph3^si- 

 ology do not explain the behavior adequately. 



We have seen also that extended examination is not caused 

 by the mere presence of the hairy caterpillar, for its first appear- 

 ance did not call forth examination. The real cause of the ex- 

 amining process is the experience which the frog had with the 



