resent any such association of superfertility or
infertility with desirable or undesirable traits. It is obviously the
aim of Eugenics to bring about an association of a high degree of
fertility with desirable traits and a low degree of fertility with
undesirable characteristics.

First, let us look at certain data gathered relative to the size of
the family in both normal and pathological stocks (Table II). In order
that a stock or family should just maintain its numbers undiminished
through successive generations and under average conditions, at least
four children should be born to each marriage that has any children at
all.

TABLE II

_Fertility in Pathological and Normal Stocks._ (From Pearson)

NATURE OF MARRIAGE. NO. IN
AUTHORITY. (Reproductive period.) FAMILY.

Deaf-mutes, England Schuster Probably complete 6.2
Deaf-mutes, America Schuster Probably complete 6.1
Tuberculous stock Pearson Probably complete 5.7
Albinotic stock Pearson Probably complete 5.9
Insane stock Heron Probably complete 6.0
Edinburgh degenerates Eugenics Lab Incomplete 6.1
London mentally
defective Eugenics Lab Incomplete 7.0
Manchester mentally
defective Eugenics Lab Incomplete 6.3
Criminals Goring Completed 6.6
English middle class Pearson 15 years at least,
begun before 35 6.4
Family records--normals Pearson Completed 5.3
English intellectual
class Pearson Completed 4.7
Working class N.S.W. Powys Completed 5.3
Danish professional
class Westergaard 15 years at least 5.2
Danish working class Westergaard 25 years at least 5.3
Edinburgh normal
artisan Eugenics Lab Incomplete 5.9
London normal artisan Eugenics Lab Incomplete 5.1
American graduates Harvard Completed 2.0
English intellectuals Webb Said to be complete 1.5

All childless marriages are excluded except in the last two
cases. Inclusion of such marriages usually