332 'Journal of Comparative Neurology atid Psychology. 



unity, by Professor Judd. In general, lateral movements ot both eyes in the same 

 direction are a more thoroughly established form of coordination than are move- 

 ments of convergence and divergence; but many particular facts of movement are 

 brought out which are well worth studying in detail. As is well known, the author 

 denies the significance ordinarily attributed to sensations of movement in the forma- 

 tion of spatial and other percepts, and his view is expressed in the very pregnant and, 

 in the reviewer's opinion, just proposition: "The only concept which is of any value 

 in the clear explanation of perceptual unity is the concept of coordination," i. e., 

 the coordination of motor response. E. B. H. 



The Archives of Psychology. Edited by R. S. Woodworth. Xew Fork, The Science Press. 



The Archives of Psychology is a continuation of the psychological part of the 

 /Archives of Philosophy, Psychology, and Scientific Methods, of which one volume, 

 consisting of the following monographs, was published. 



Measurements of Twins. By Edward L. Thorndike. 



Avenarius and the Standpoint of Pure Experience. By Wendell T. Bush. 



The Psychology of Association. By Felix Arnold. 



The Psychology of Reading. By Walter Fenno Dearborn. 



The Measurement of Variable Quantities. By Franz Boas. 



Linguistic Lapses. By Frederic Lyman Wells. 



The Diurnal Course of Efficiency. By Howard D. Marsh. 



The Time of Perception as a Measure of Differences in Sensations. 



By Vivian Allen Charles Henmon. 



Below we give review notices of the numbers of the Archives of Psychology 

 which have appeared. 



Norsworthy, Naomi. The Psychology of Mentally Deficient Children. Archives of Psychology, no. 

 1, pp. iii + I II. $1.00. 1906. 



The author presents the results of an experimental study of groups of defective 

 children, and discusses the scientific and practical significance of the facts which 

 she has discovered. She briefly summarizes what little experimental work had 

 been done in this field, previous to her own investigation, and insists upon the need 

 of the exact measurement of a number of the important characteristics of normal 

 and defective children. 



"I have sought to determine," she writes, "(i) whether the mental defects of 

 idiots are equaled by the bodily, (2) whether idiots form a separate species or not, and 

 (3) whether the entire mental growth is retarded, that is, whether there is a lack of 

 mental capacity all around." In order to get data for the solution of these problems 

 she made measurements of the following traits. Mental Traits: Efficiency of 

 perception; memory of unrelated ideas; ability in the formation of abstract ideas; 

 ability to appreciate relationships and to control associations; perception of weight; 

 and motor control. Physical Traits: Height; weight; pulse and temperature. 



The measurements which were made led the author to conclude: (i) That there 

 is a decided difference between bodily and mental deficiency (p. 69); (2) that idiots 

 seem not to form a special class or species, at least as far as intellectual traits are 

 concerned, but that they are included as part of a large distribution (p. 77); and (3) 

 that there is not among idiots an equal lack of mental capacity in all lines (p. 82). 

 Of special interest to educators, and to others who are interested primarily in 



