410 C. C. HURST 



cell. The next step therefore is to attempt to place the problem of the in- 

 heritance of intellectual abilities on a genetical basis. 



To this end a personal investigation continued over a number of years, has 

 been made of 194 families representing various occupations and conditions 

 of life in my native district in Leicestershire. The same families were stud- 

 ied for the determination of the inheritance of Eye-Colour (1908), (1912), 

 (1925), (1932 B) and for the inheritance of various physical characters and 

 musical temperament (1912). Except for the five years of war 1914-1919, 

 these families have been repeatedly studied for intellectual abilities since 

 1904, and are still being followed up. The research has involved detailed 

 comparative studies of the intellectual activities and achievements of 388 

 parents and their 812 offspring (L. F. data). To these results have been 

 added the definite data presented by Woods of 212 families of European 

 Royalties and their relations. This research covers a period of several cen- 

 turies and includes definite studies of 424 parents and their 558 offspring 

 (R. F. data). The combined data thus cover a space-time population of 

 812 parents and their 1370 adult offspring, analysed in 406 separate families 

 (Table 1). 



Woods rates the intellectual abilities of individual Royalties and their 

 relations in ten grades, from the lowest grade 1 to the highest grade 10. In 

 his mental gradings, Woods, like Galton, relies on historical reputation, i.e., 

 contemporary opinions critically revised by posterity. He takes the con- 

 sensus of opinion among biographers and historians and systematically aver- 

 ages or modes these on the basis of the particular adjectives and character- 

 isations used. For my modern data similar grades have been adopted but 

 the ratings have been determined on the basis of an intimate personal knowl- 

 edge of the intellectual activities and achievements of the individuals graded. 

 In order however to bring the ratings into line with the genetical formula 

 and the juvenile I.Q., an eleventh grade O was added, making a scale of 

 equal grades, each equivalent to 20 I.Q. (table 1). It is interesting to find 

 that the two sets of data derived from such radically different sources and 

 conditions of life and rated by different methods, do not essentially differ 

 from one another either statistically or genetically, the most striking feature 

 common to both being the overwhelming excess of the numbers of the mediocre 

 grade 5 over the adjacent and remaining grades and the extreme rarity of 

 the highest and lowest grades (table 1). In the Leicestershire families, as 

 might be expected in a small sample of a rural population, the two highest 

 grades 9 and 10 are absent and it is significant that the 4 individuals of grade 

 8 found in the district have all left for a wider sphere of work. 



It is difficult to conceive two sets of material more widely different than 



