354 Life ami Tetters of Frauds Calton 



struggle for existence, and that it is of interest to know what these sub- 

 types are. The colour of animals is often found to be intimately correlated 

 with their power or incapacity to thrive under certain conditions, and it 

 may well be the same in the avse of man. Galton cites Baxter' to prove 

 that in America, where the pressure of life peculiar to modern civilisation is 

 even greater than with us, the black-haired persons are less liable to nearly 

 every form of disease than the fair-haired. He observes, however, that it is 

 needful at the same time to determine the relative fertility of the light and 

 dark haireil. and that it would be very important to distinguish between the 

 children of a dark-haired man who had sprung from a light-liaired stirp, and 

 those of a similar man from a dark -haired stirp. The schedule is fairly straight - 

 forwanl and contains the first statement of Galton's system of numerals for 

 relationship, i.e. child 1, parents '1, 'A, grandparents 4, 5, 6, 7, etc., the even 

 numbers standing for males and the odd for females (No. 1 excepted, which 

 may have either sex) ; the number of any individual when doublea gives that 

 of his father, and his mother's number is obtained by the addition of our 

 to the number of his father'. The characteristic Galtonian statement is 

 made incidentally that : 



"Th« inquiry will have the merit of being accompanied by incidental pleasures; it will bt> an 

 excuse for corresponding with distant friends and relations on topics of common interest, and 

 it is probable that not a few facts of family history much prized by its members will in many 

 caaee be incidentally brought to light by its means." 



Galton himself was so interested in family history that he quite naively 

 overlooked the fact that nine-tenths of humanity either fear to examine it 

 or are frankly bored by it. Against that dead-weight of inertia Galton 

 could effect little, and there is no evidence that these circulars were ever 

 returned in sufficiently adequate numbers to serve as a basis for an answer to 

 his inquiry. 



' Medical and Anthropological Statistics o/the Provost- Afarshal-GeneraTs Bureau, Washing- 

 ton, 1875. 



* Galton published a letter on this numerical system of relationship in Nature, Sept. 6, 1883, 

 under the title: "Arithmetic Notation of Kinship." Taking y=: father of, m = mother of, hi' 

 gives the following equivalent systems of notation: 



Literal System. Child 



etc. etc. 



The Binary System is cumbersome but simple, we add a zero for the father and a unit for 

 the mother of any individual to that individual's numlter. The decimal system is as follows: 



