THE CANADIAN ENTOMOLOGIST. 269 



I 



BOOK NOTICE. 



The Psychical Powers ok Ants.*— By E. Wasmann, S. T- 



In this folio volume of 135 pages, which appears as " Zoologica, 

 Heft 26," the author has given us his 95th contribution to the knowledge 

 of guests and parasites of the ants and termites. As the title shows, the 

 work is of a philosophical nature and deals with the mental side of ant- 

 life, being in the main concerned with a refutation of the theory recently 

 advanced by A. Bethe, who ascribes to ants and other invertebrates in 

 general, no higher psychological rank than that of mere "reflex-machines." 

 The introduction reviews in brief the views of various earlier writers 

 on the subject, and indicates the author's position, in that while rejecting 

 Bethe's reflex theory, he also avoids the tendency exhibited by many 

 naturalists to ascribe to ants powers of mind approaching those of man. 

 Next follows a chapter devoted to an analysis of Bethe's theory, and 

 showing Dr. Wasmann's reasons for the rejection thereof. In this 

 connection the author writes : " It appears to me a reliable criterion 

 that the animals concerned are not mere reflex-machines, but are guided, 

 at least in the higher activities of life, by sensory perception and sensation 

 on a foundation of inherited instinct is to be found in this : the possession 

 of special sense organs in combination with a central nervous organ, as 

 well as their manifold and suitable employments through which the 

 animal turns impressions from the outside to use in the necessities of its 

 life." 



The succeeding chapter considers the question, "How do ants know 

 one another ? " And here much evidence is brought forth to show that the 

 recognition is due to sensory perception, and is not automatic. The 

 antennae (especially the tips) are concerned in the discrimination, and Dr. 

 Wasmann agrees with Porel that the detection of odour is very largely 

 depended upon therefor. The subject next approached is " How do 

 ants find their way ? " Reference is made to the well-known fact that 

 with many species a definite path is followed during journeys to and from 

 the hunting-grounds, while in other species the wanderings are made 

 much at random. Not only are ants able to follow their paths, but they 

 also discern the direction in which the trail leads: /. e-, if it is running 

 towards the nest or from it. Bethe has advanced his theory of the 



*Uie psychischen Fahigkeiten der Ameisen. Von E, Wasmann, S. J. Stutt- 

 gart, Erwin Nagele, 1899. 



