476 WALTER S. HUNTER 



are found at all. In some cases they are not even brought 

 to the reader's attention in the subject index. One such case 

 is that of tactile and auditory hairs. A volume placing emphasis 

 upon sensory discrimination should contain a discussion or a 

 summary of methods with evaluating comments thereon. This 

 would give the reader a guide to the reliability of the data 

 presented. An actual examination reveals that the method of 

 general response is very universally applied. This can be 

 supplemented by extirpation studies with certain forms. The 

 association method in any definite form has not been so ex- 

 tensively used with the invertebrates. Further criticism in this 

 same vein may be directed against the author's bibliography. 

 Although this does not aim at completeness, it does aim at the 

 inclusion of the most important works and of the most repre- 

 sentative general references. The list given covers 28 pages. 

 In the general list one misses such titles as: Wheeler "Ants"; 

 Holmes "Evolution of Animal Intelligence"; and Max Meyer's 

 "Laws of Human Behavior," — which last deserves a place equally 

 with many that are included. Other sins of omission might 

 be indicated here and in the bibliographies in special subjects. 

 I will call attention only to the lack of reference to Mclndoo's 

 "Lyriform Organs and Tactile Hairs of Araneads" and to the 

 articles on taste and smell mentioned below. American inves- 

 tigations are referred to with great frequency. 



One of the very excellent features of Kafka's work is the 

 large number of illustrations given, — a total of 362 figures. 

 These present the gross bodily appearance, the detailed anatomy 

 of the sense organs and certain types of reactions of the animals 

 concerned. Comparative psychologists will welcome a conven- 

 ient summary of invertebrate sense organs. The teaching of 

 the subject will gain by this emphasis upon structure even if 

 research work does not need correction and an added incentive. 

 Pedagogically important also are the references to the tropic 

 activities of bacteria and the sex cells. 



The intimate relations between touch and hearing are pointed 

 out. The existence of auditory hairs furnishes supporting 

 evidence here. No claim is made that the phenomena treated 

 under audition are to be interpreted as essentially different 

 from those of touch. The differentiation must be in terms of 

 stimuli and these are proverbially hard to control. The general 



