This phenomenon which as yet has received much too little attention is +the large scale on which families die out+, at first in the male line. Apparently (sufficient observations for control are not available) those families which hold an eminent economical or social position (aristocracy, old county families, etc., etc.) are mainly concerned. Because exceptional endowment in one or more respects (intelligence, talent, will power, etc.) is generally required to secure or to maintain a leading position, and because such endowment is given to only a small fraction of the population, but is inherited largely by the progeny, this dying out of the leading families means a serious loss to the race. The deficient fertility of the stock thus endowed results in a lower average of mental capacity in the population generally, and cannot in the long run be made up by the constant re-appearance of distinguished men appearing as variations, the smallest number of whom are "mutations." The tendency among town families to die out appears to be wide-spread. Professor S. Schott in Tables C 37-C 40 adds materially to our knowledge on this point, Professor Schott makes the following comment on his Tables:-- "S. Schott. Old Mannheim families, 4 tables." "Source: 'Old Mannheim families. A contribution to the family statistics of the 19th Century by Professor Dr. Sigmund Schott, Mannheim and Leipzig, 1910. J. Rensheimer.' Statistical demonstration of the development, decline, and extinction of about 4,000 families which were in existence at Mannheim at the beginning of the 19th Century, based on permanently maintained family registers. This research, pursued on a basis of population statistics, lends itself only to a limited degree to application for biological purposes." [Sidenote: C 37] +Gradual extinction of the Mannheim families in the 19th Century.+ Only extinction by death in Mannheim and in the male line are taken into account. Families which have disappeared through emigration have been excluded. Branches of families which have become extinct at Mannheim may be flourishing elsewhere. Of 3,081 families, 2,538 have become extinct by death at Mannheim itself, 543 survive. The spiral curve shows the number of survivors in any year as so many per thousand of the original number. [Illustration: Old Mannheim Families. Gradual extinction of Old Mannheim Families during the 19th century. Figure C 37.] [Sidenote: C 38]