Page:Proceedings of the Royal Society of London Vol 69.djvu/162

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Prof. K. Pearson.

were not very copious, and in default of a method of dealing quantitatively with characters not capable of exact scaling, it was not possible to deduce absolutely conclusive results. Still Mr. Galton brought good evidence to show that temper and artistic instinct were inherited characters. On November 19, 1899, a paper was read to the Royal Society showing how the inheritance of characters not capable of exact quantitative measurement might be deduced. In that paper I dealt with Mr. Galton's statistics, and showed that the fraternal correlation in the matter of temper was O3167, and the parental corre- lation in the matter of artistic instinct was O g 4039. These numbers are somewhat low and not altogether satisfactory. I purpose in this preliminary notice to give only a few results from some very elabo- rate observations which have been made in the course of the last few years.

(2.) The material was collected in two separate ways. In the first series the Family Measurement Series only physical characters were observed. This series was started six years ago, and upwards of 1100 families, father, mother, and not more than two sons and two daughters, were measured. The series was closed two years ago, and last year Dr. Alice Lee completed the reduction of this very large mass of material. In its reduced form seventy-eight correlation tables have been formed, giving as many correlation coefficients bearing on direct or cross heredity. This is probably the most extensive series of inheri- tance coefficients each based, as a rule, on upwards of 1000 pairs which has yet been obtained.

My second series will be still more extensive ; but it relates only to collateral fraternal heredity. It aims at observing a wide range of both physical and mental characters in pairs of school children. I have received most kindly aid from a great number of masters and mistresses in public schools, high schools, secondary and primary schools of all classes. This will be very fully acknowledged in the final publication of the results. But although the work has been in progress for three years, we have still only material enough to draw conclu- sions in the case of pairs of brothers, of whom more than 1000 cases have been observed.

The work has been carried on with the assistance from the Govern- ment Grant of a sum appropriated to this purpose in 1898. Without this aid it would not have been possible for me to purchase the neces- sary head-spanners or to circulate them among the schools.

(3.) Only three of the physical measurements of this extensive series have yet been reduced, and the sister-sister and sister-brother observations will have to be carried on for another year or two before they are sufficiently numerous. The whole material will then require two or three years for tabulation and calculation. But as the problem of the inheritance of the mental characters and their correlation