ge_" shows that in the early tribe there was no inhibition
against the marriage of blood relations; that the restriction then was
against the members of the tribe that used one tent; these might or
might not be blood relations. The traditions and folk-ways against the
marriage of close relations grew from the familiarity that came from the
living together of brother and sister, for instance, in one home. This
feeling gradually worked itself into custom and habit and from that into
folk-ways and laws. Sometimes we read accounts of the marriage of a man
and woman who found, after years had gone by, that they were brother and
sister who had been separated in infancy and grew up without knowledge
of their relation to each other. Whether Nature forbids the marriage of
relatives by preventing offspring or by producing imperfect offspring is
a doubtful question. Certain communities in Europe have lived together
so long that all are related and still they seem to thrive. Considering
the general custom and feeling on the subject, however, the man and
woman who know that they are closely related and who marry are different
and weaker than the others; and this may show in their offspring.
Although the subnormal may have no such feeling, they are judged by the
traditions and customs of the normal and on that judgment are sent to
prison.

Many sex crimes are charged to children in the adolescent age; children
who have no knowledge of sex and its development and are helpless in the
strength of their newly-discovered feelings. This class of offenders is
almost always the inferior and the poor who are moved by strong
instincts which they have not the natural feeling, the strength, the
education, nor the desire to withstand.

While most crimes against persons are not directly due to economic
causes, still the indirect effect of property is generally present in
these crimes as well as others. The fact that the poor and defective are
generally the subjects of prosecution and conviction in these offences
shows how closely economic conditions are related to all crimes.

Other criminal statutes are of more modern date, and as a rule involve
not much more than adultery, except in regard to the age of the girl
offender, which is generally placed below eighteen. Still the sex age of
neither boys nor girls can be fixed by a calendar. It depends really
upon development, which is not the same with all people or in all
environments. Many girls of