72 NATURAL INHERITANCE. [MAP.
to say nothing of its being more interesting by far than one of sweet peas or of moths.
Record of Fanzily Faculties, or I.F.F. Dates.-The source from which the larger part of my data is derived consists of a valuable collection of "Records of Family Faculties," obtained through the offer of prizes. They have been much tested and cross-tested, and have borne the ordeal very fairly, so far as it has been applied. It is well to reprint_ the terms of the published offer, in order to give a just idea of the conditions under which they were compiled. It was as follows
" Mr. Francis Galton offers 5001. in prizes to those British Subjects resident in the United Kingdom who shall furnish him before May 15, 1884, with the best Extracts from their own Family Records.
" These Extracts will be treated as confidential documents, to be used for statistical purposes only, the ,insertion of names of persons and places being required solely as a guarantee of authenticity and to enable Mr. Galton to communicate with the writers in cases where further question may be necessary.
" The value of the Extracts will be estimated by the degree in which they seem likely to facilitate the scientific investigations described in the preface to the `Record of Family Faculties.'
" (a) By including every direct ancestor who stands within the limits of kinship there specified. " (b) By including brief notices of the brothers and