No. I.] ORGANIC VARIATION. 295 
commences to influence the organism, the latter cannot at first be 
adapted to this new environment, but must become, so to speak, 
out of touch with it. This change of environment must then 
influence the organism, primarily, by disturbing or interrupting 
the correlation of its organs. For even should the change of 
environment interrupt directly the physiological action of only 
one of the organs, this particular organ would no longer be 
capable of acting in concerted harmony with the other organs, 
and thus the correlation of the whole would be disturbed. For 
example, if the customary food supply become exhausted, so 
that the organism is compelled to seek nourishment of a dif- 
ferent kind, not only in the immediate intestinal cells must a 
physiological (and consequent morphological) change ensue, 
but also the structure and function of each organ, indirectly 
dependent upon the intestine’s action, must become modified. 
And, pari passu, if the external forces acting upon a sense- 
organ assume a different direction, not only must this particular 
organ become physiologically modified, but indirectly also the 
nervous system, and all organs in functional communication 
with the latter; or if a certain organ become diseased, its 
normal action must become to some extent impeded, which 
would exert an influence upon the functions of the other 
organs. In fact, whatever organ be directly influenced by a 
change in the environment, a modification of the functions and 
structure must result in those organs which are in correlation 
with it. 
Accordingly, after a change in the environment, a temporary 
disturbance of the correlation of the organs must result. When 
we speak in this way of an “interruption ”’ or of a “disturbance” 
of the correlation, we mean that the mutual dependence of the 
several organs upon one another is reduced, so that they become 
to an inverse extent independent of one another. Now I con- 
sider that the origin of variation is to be found in this condition 
of temporary independence of the organs, which independence 
is caused by change of environment, resulting in the partial 
interruption of the organs’ correlation. For each organ, after 
the disturbance of such mutual correlation, becomes more az‘o- 
dynamic, —more indep¢éudent of the restraining influences of 
