544 General Notes. 
and fixed by the primary cause of prepotency, usefulness to the 
individuals themselves. 
The function of atavism is in all probability that of serving as 
a restraining influence against what might otherwise be a too 
rapid divergence in any one direction, before surrounding and 
semi-dependent parts, and special instincts have become modified 
in such a manner as to functionate harmoniously with it. To 
illustrate; a too sudden change of color presenting itself, and 
becoming inherited in a species of bird, dependent upon it toa 
certain extent for protection, would, if occurring before its mental 
attributes had sufficient time to evolve with, and adapt themselves 
to it, tend towards the extinction of the individuals manifesting 
it, from a failure of the instinctive actions to properly 
their offices in producing the protective effects intended, while 
the individual cases of atavism of color, with unchanged in- 
stincts, would escape. So by the continual preservation nese 
a fixed law, acting as a governor to the organisms over which it 
variability, as to best serve their interests. Though in it we may 
also find the explanation of the extinction of some of the 
races of the past, in whom, on account of the want of se 
incentives to struggle for existence, they remained stationary ong 
enough to allow it to become thoroughly fixed, and thus b ve" 
so prepotent over the natural adaptive inclinations of variability 
by the action of selection to assume the new and n nter- 
modifications demanded by changes of environment, as to year be- 
act all such tendency, and, by so overreaching itself, in fact, 
come suicidal in its nature. ch an inheri- 
and 
cestors, as well as retaining landmarks of the more pr In 
‘in contact with disturbing, physic 4 
by which some change in the sy a i 
in one or more parts, takes effect at th oped. q 
certain stages of varietal divergence are being deve ree | 
An arresting of divergence does not noin wn 
power to develop to maturity, but will often produc vietal evol- 
be termed premature development. Therefore th; vertain varie 
tion being arrested by certain disturbing ion form or reve 
germs are aborted, and the product is a prepare? 
