THE ANTHROPOLOGICAL SOCIOLOGISTS 161 
inventions ! and social institutions, racial differences ? and early 
migrations. For example the historical investigations of Sir 
Henry Maine left the question of the pre-historic family un- 
touched save by inference. The anthropological researches of 
Bachofen, McLennan, Morgan and Lubbock have come to be 
considered as based on insufficient and misleading evidence, and 
the most potent weapon of criticism of their conclusions, as used 
by Spencer, Howard, Westermarck and others, is just this theory 
of adaptation. Granted that primitive people were ignorant of 
the relation between copulation and child-birth, we may still 
argue for a more or less permanent relation between the sexes 
from monogamic mating among birds and higher mammals, from 
jealousy, and from economic need, also from the more recent 
studies of sex mores among extant types of primitive culture. 
Moreover, whatever the first form, promiscuity could not prevail 
because of its dis-utility owing to its connection with venereal 
diseases and low fecundity, and because of its effect on childhood. 
Thus the earliest form and changes in it were in accordance with 
this principle of adaptation. 
1 Mason, Origin of Inventions, ch. I. 
2 Marett, Anthropology, pp. 93 f.; Keane, Ethnology, ch. X; also Man Past and 
Present, p. 13; Boas, op. cit., ch. II. 
3 Chapin, Social Evolution, pp. 141 f. 
