548 



SCIENCE 



[N. S. Vol. XXXIX. No. 1006 



ity there appears to be some correlation by the 

 method of comparison, yet when computed by 

 Pearson method the index of correlation is very 

 small. The coefficients of correlation calculated 

 by the Pearson method are as follows: 



Men Women 



Weight and class standing 056 .052 



Height and class standing 023 .216 



Vital capacity and class stdg 085 .245 



Cephalic index and class stdg.... — .033 — .151 



In summing up the foregoing, it appears that 

 the measurements in this series have little interde- 

 pendence. 



The index of correlation except in the case of 

 the vital capacity of women, is a negligible quan- 

 tity. However, the number of cases is too small 

 in our investigation to justify the statement of 

 any general conclusion or law. It may be said, 

 nevertheless, in the hundred cases studied, there 

 seems to be little, if any, correlation between men- 

 tal ability, as shown by class standing of college 

 students, and height, weight, lung capacity and 

 cephalic index. 

 The Causes of the Declining Birth-rate: J. Mc- 



Keen Cattell. 



The completed family of contemporary scien- 

 tific men is about 2, the surviving family about 

 1.8 and the number of surviving children for each 

 scientific man about 1.6. Twenty-two per cent, of 

 the families are childless; only one family in sev- 

 enty-five is larger than six. The same conditions 

 obtain for other college graduates. The speaker 

 discussed the biological causes through which the 

 fertility of a woman has been limited to an aver- 

 age of about twelve children, the social causes 

 which lead about one half of all women of child- 

 bearing age to remain unmarried, and the patho- 

 logical and psychological causes which give the 

 present family of two or three children. Answers 

 liad been received from 461 leading scientific men 

 giving the causes which led to the limitation in 

 the size' of their families. One hundred and sev- 

 enty-six were not voluntarily limited, while 285 

 were so limited, the cause of the voluntary limita- 

 tion being health in 133 cases, expense in 98 eases 

 and various other reasons in 54 cases. Childless- 

 ness was involuntary in two thirds of the cases. 

 In the standardized family of two the condition 

 is desired in six oases out of seven. In over one 

 third of the families the limitation was involun- 

 tary, due to infertility and other pathological 

 causes, but if these had not obtained, voluntary 



limitation would have occurred in nearly all or 

 perhaps in all cases. 



On the Effect of Adaptation on the Temperature 



Difference Limen: Edwina Abbott. 



The effect of adaptation to different tempera- 

 tures on the difference limen for 40° C, 37.5° C, 

 35° C, 32.5° C, 30° C, 27.5° C, 25° C, 22.5° C, 

 20° C. and 17.5° C. was determined. Water was 

 used as the adaptation medium and was kept at 

 any desired temperature by means of an electric 

 heater controlled by an electric thermostat. The 

 fingers of both hands of the subject were adapted 

 to a certain temperature as far as the second 

 joint and when adaptation was complete the fin- 

 gers were raised and those of one hand dipped into 

 water of the standard temperature and those of 

 the other hand into water of the variable tem- 

 perature for the difference limen test. The method 

 of right and wrong cases was used in determining 

 the limen and the fingers readapted before each 

 test. Tour trained subjects were used. 



The results indicate that: (1) The difference 

 limen for a given temperature after a given adap- 

 tation temperature is relatively constant for a 

 given individual; (2) the absolute amount of the 

 difference limen under such circumstances differs 

 for individuals, but the relation between the limina 

 for different temperatures after any given adap- 

 tation temperature remains the same for different 

 individuals; (3) the point of greatest sensitivity 

 to difference lies at 32.5° C; (4) the preceding 

 adaptation temperature affects the difference 

 limen for a given temperature, the difference 

 limen, in general, increasing as the adaptation 

 temperature varies from the standard tempera- 

 ture; except for 32.5° C. where the difference 

 limen remains constant under all conditions of 

 adaptation. 



Eventually to appear in the Psychological Be- 

 view, Monograph Series. 



A Study of the Behavior of the Chick: Ada Haet 



Arlitt. 



In February of 1913 work suggested by that of 

 Ferg on the effect of alcohol on the physiological 

 development of the chick was undertaken in the 

 biological laboratory of Newcomb College. It 

 was found possible to raise healthy chicks from 

 eggs which had been subjected to alcoholic treat- 

 ment, but the behavior of these chicks differed 

 from that of normal chicks hatched in the same 

 incubator at the same time. 



The reactions to light and the pecking and 

 drinking reactions of the abnormal chicks differed 

 but little from those of normal chicks. 



