No. 502] 



NOTES AND LITERATURE 



statistical standpoint. Heron, on this point, makes the follow- 

 ing just and timely complaint. 



A careful examination of the annual Reports of the Asylums of 

 Great Britain and Ireland has led to the conviction that no data at 

 present published would enable the statistician to reach any quantitative 

 results as to the inheritance of any single form of brain disease: Even 

 medical treatises as a rule go no further than stating the percentage of 

 cases in which insanity or some other want of mental balance has been 

 recorded in the family history. As long as we do not know the total 

 number in each class of relatives of the insane person and the exact 

 brain defect from which they have suffered; as long as we do not know 

 the total number of relatives of a random sample of the sane population 

 and the exact forms of neurosis or brain disease from which they too 

 have suffered, any attempt at a full treatment of the " inheritance of 

 insanity" is from the statistical standpoint idle. What advantage can 

 possibly arise from telling us that an insane person has so many 

 alcoholic uncles if we do not know either the total number of his parents 

 brothers and sisters, or the percentage of alcoholic members in the same 

 grade of relationship of a sane individual of the same social class? 

 . . . The solution of this difficulty, and the present writer believes 

 of many other difficulties in the statistics of insanity, is to establish a 

 General Register of the Insane for preservation in the office of the 

 Lunacy Commissioners. 



Heron's own work is based upon an analysis ot'ool family trees 

 provided by Dr. A. R. Urquhart, physician superintendent of 

 the James Murray's Royal Asylum, Perth, Scotland. The co- 

 efficient of parental inheritance is found to be about r = .50 and 

 fraternal resemblance r = .45 — .55. These are in close accord 

 with other physical and mental measurements. The author is 

 obliged to make several assumptions in regard to the general 

 population in order to complete his calculations, so that his 

 figures must be regarded as only a first approximation. The 

 work is certainly in the right direction and it is to be hoped 

 that all alienists will carefully read this valuable memoir. 



Miss Elderton and Pearson 7 have published a measure of the 

 resemblance of first cousins, especially in such characteristics as 

 general health, intelligence, success, temper, temperament (re- 

 served or expressive, sympathetic or callous, excitable or calm). 

 Their correlation coefficients are not very uniform, but they 

 show clearly enough a high degree of cousin resemblance, r 



1 Eugenics Laboratory Memoirs. IV, On the Measure of the Kesem- 

 blance of First Cousins. By Ethel M. Elderton, assisted by Karl Pearson 

 London, Dulau and Co., Soho Square, W., 1907. 



