THE ROVING IMPULSE 193 
the expectation is that all the children will be.” As 
to the not infrequent concomitance of nomadism 
with periodic abnormal psychoses, such as de- 
pression or hysteria, Dr. Davenport thinks that this 
simply means that these abnormal states weaken 
or paralyze the usual inhibitions, and thus allow 
the nomadic impulse to assert itself. He is con- 
vinced that nomadism is a perfectly definite herit- 
able character. 
The second question is whether “roving” is a 
new variation—a germinal experiment so to speak, 
or an atavism in the wide sense—a reversionary 
outcrop of an antique and once widespread human 
instinct. Or it may be that there are two types. 
Dr. Davenport regards nomadism rather as a 
negative than as a positive trait, holding that the 
characters which normally make for steadiness 
and settling-down are weak or absent, with the 
result that a primitive wandering impulse finds 
uninhibited expression. As he states it, in modern 
phraseology, “the nomadic impulse depends upon 
the absence of a simple sex-linked gene that ‘ deter- 
mines’ domesticity ”’—“ gene” meaning a “ unit- 
factor” or particular component in the germinal 
inheritance. On this view, we are all bearers of the 
vestiges at least of an ancient wandering instinct 
supposed to be primitive in mankind, but we 
normally inhibit or regularize its development or 
expression. This inhibition comes about organi- 
cally, because less primitive characters, such as 
having and loving a home, are stronger than the 
