xii Journal of Comparative Neurology. 



sive stimulation of the same taste-surface. The contrasts of sweet and 

 sour could only be observed in the latter case. 



4. Bitter forms an exception, but yet perhaps gives rise to con- 

 trasts restricted to individuals. 



Studies from the Yale Psychological Laboratory. 



The second volume of these studies was issued in November last. 

 The first article by Professor Scripture, On Mean Values for Direct 

 Measurements, devotes 40 pages to a technical mathematical discus- 

 sion largely concerned with the median as an instrument in psycho- 

 logical research. 



The second paper, Researches on the Mental and Physical De- 

 velopment of School Children, by J. Allen Gilbert, details the results 

 of a series of tests made upon about a hundred children from 6 to 17 

 years of age, each child being tested in the following respects : muscle- 

 sense, sensitiveness to color-differences, force of suggestion, voluntary 

 motor ability, fatigue, weight, height, lung-capacity, reaction-time, 

 discrimination time, and time-memory. 



The results of the first test give in grams the threshold for dis- 

 crimination to weight for each child. There is a gradual increase in 

 ability to discriminate from the ages of 6 to 13, which is tolerably 

 uniform except for a temporary abrupt falling off for boys at 11. The 

 sensibility is strongly diminished for girls at 13 and for boys at 14, 

 after which it slowly increases. The curves of color discrimination 

 are far more irregular. 



The force of suggestion was studied along lines similar to those 

 followed by Dressier, as published last year in the American Journal 

 of Psychology (cf. review in this Journal, Vol. IV, p. cxxxii), though 

 with slightly different apparatus and some difference in the results. 

 Of blocks equal in weight, but differing in size the smallest were al- 

 ways judged the heaviest, the girls making greater errors than the 

 boys. Dresslar found this illusion to be stronger in bright children 

 than ill dull and stronger in adults than in children. On the other 

 hand, Gilbert finds the illusion to increase up to nine years, then to 

 diminish to puberty, increasing slightly until 15 years old for boys and 

 16 years for girls, after which it again diminished to 17 years. 



The voluntary motor ability was estimated by counting the num- 

 ber of taps which a child can make in 5 seconds. Boys tap more 

 rapidly than girls and both show a diminished rate at puberty. 



The average reaction-time of all ages for bright children was 

 20.7 hundredths of a second ; for those of average abiHty it was 21.3; 



