INSTITUTIONAL AND PRUDENTIAL SELECTION. Til 
We may also assume that increased segregate fecundity and vigor 
will make the multiplier for pure-breeds = 2, and the multiplier for 
. cross-breeds = j. And when another ten generations have passed, 
still higher degrees of segregation will be the natural result. 
Conclusion.—We have now approached in three different ways 
the proof of cumulative advance in a set of innate qualities, which 
by their combined action produce in moderate degress both positive 
and negative segregation. The result seems to be that when 
by any chance comes to be larger than Mc + m, then the fraction 
mc 
M—Mc—m 
becomes a positive quantity, and a given proportion of the whole 
stock remains unaffected by crossing. This point having been reached 
the subsequent tendency is toward a constant increase in the segre- 
gative endowments. 
, which gives the ratio of cross-breeds to pure-breeds,* 
18. Institutional and Prudential Selection. 
Institutional and prudential selection stand in the same relation to 
the other forms of reflexive selection that artificial selection holds in 
relation to natural selection. They are the forms of reflexive selec- 
tion established in communities of rational beings for the purpose of 
securing ends that are more or less fullv apprehended as the goal. 
It should be observed that inherited instincts have an important 
part in each of the forms of conjunctional selection, that is, in sexual, 
social, and filto-parental selection; and again in the forms of impreg- 
national selection and impregnational isolation just discussed, the 
coordinations are due to inherited characters, either morphological 
or physiological; but in institutional and prudential selection the 
processes are guided by conscious and reflective purpose. It will, 
therefore, be seen that the conscious regulation of relations between 
husband and wife, between man and man, or between parents and 
children, when it affects the form of survival, belongs to either insti- 
tutional or prudential selection, and not to conjunctional selection 
in any one of its three forms. In the past history of man the three 
forms of conjunctional selection have been of prime importance; but 
as civilization advances increasing control is given to institutional and 
prudential selection. Moreover, in the case of civilized man, domina- 
tional selection through intra-group struggle has in a large measure 
ceased to be a struggle for life or for the opportunity to have a full 
share in producing the next generation, and has become chiefly a 
struggle for influence in society and for escape from certain forms of 

* See Formula (4), on page 105. 
