evident that other men will probably have to forego marriage entirely.
This is not saying that under certain circumstances, namely, the
importation of large numbers of women, a higher per cent of polygynous
families may not exist. It is said that among the negroes on the west
coast of Africa the number of polygynous families reaches as high as
fifty per cent, owing to the fact that female slaves are largely
imported into that district, and that they serve not only as wives, but
do the bulk of the agricultural labor, the male negro preferring female
slaves, who can do his work and be wives at the same time, to male
slaves. But such cases as these are altogether exceptional and
manifestly could not become general.

Summing up, we may say that the causes of polygyny are, then:

(1) First of all, the brutal lust of man. No doubt man's animal
propensities have had much to do with the existence of this form of the
family. Nevertheless, while male sensuality is at the basis of polygyny,
it would be a mistake to think that sensuality is an adequate
explanation in all cases. On the contrary, we find many other causes,
chiefly, perhaps, economic, operating also to favor the development of
polygyny.

(2) One of these is wife capture, as we have already seen. The captured
women in war were held as trophies and slaves, and later became wives or
concubines. Among all peoples at a certain stage the honor of wife
capture has alone been a prolific cause of polygyny.

(3) Another cause, after slavery became developed, was the high value
set on women as laborers. Among many barbarous peoples the women do the
main part of the work. They are more tractable as slaves, and