Allen, Association in the Guinea Pig. 295 



movements is put into play by the physical or chemical proper- 

 ties of the medium. 



The insects exhibit a comparatively complex organization. 

 Lubbock and Romanes attribute a high degree of psychical devel- 

 opment to bees, wasps, spiders and ants. Dr. and Mrs. Peck- 

 ham are more conservative, but conclude that there are pres- 

 ent memory, spatial perception, and occasional adaptations of 

 means to end. 



Albrecht Kethe' represents the extreme mechanical in- 

 terpretation of insect activities, believing them to be expressi- 

 ble in terms of immediate sensory stimuli followed by the motor 

 response. 



Bethe's principal opponent is August Forel,^ whose re- 

 cent work on the ants leads him to conclude "that sensation, 

 perception and association, inference, memory and habit follow 

 in the social insects on the whole the same fundamental laws as 

 in the vertebrates and ourselves. Furthermore, attention is 

 surprisingly developed in insects." These faculties are, how- 

 ever, manifested in a feeble form. 



LoEB ^ is inclined to attribute a small amount of intelligence 

 to ants. The question here is whether these animals do or do 

 not have any psychical life. The criterion of intelligence now 

 generally used in experimental work with lower animals is that 

 of educability. Loeb "* discusses the distribution of the associa- 

 tive processes among the lower animals. When his book was 

 published only tree frogs, among frogs, were known to possess 

 memory. 



Yerkes,^ in an extended series of careful experiments, 

 finds that the green frog has associative processes, but that as- 



' Bethe. Diirfen wir den Ameisen und Bienen psychische Qualitalen 

 zuschreiben ? Arch. f. d. ges. Phvsiolcgie (PFLtJGER's), LXX, p. 15, 189S. 



''■ FoREL. Ants and Some Other Insects. (Translated by W. M. Wheeler.) 

 Monist, Vol. XIV, pp. 3.^-66, 177-193, 1903-1904. 



^ Loeb. Comparative Physiology of the Brain, igo2, p. 224. 



* Loc. cit., pp. 219, f. 



* Yerkes. The Instincts, Habits and Reactions of the Frog. Harz^ard Psy- 

 cholcgtcal Studies, Vol. I, 1902. 



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