82 
this point may appropriately be inserted 
here. 
Darwin wrote: 
“Hence I look at individual differences, 
though of small interest to the systematist, 
as of high importance for us, as being the 
first step toward such slight varieties as are 
barely thought worth recording in works on 
natural history. And I look at varieties 
which are in any degree more distinct and 
permanent as steps leading to more 
strongly marked and more permanent va- 
rieties; and at these latter as leading to 
sub-species and to species. * * * Tattribute 
the passage of a variety from the state in 
which it differs very slightly from its parent 
to one in which it differs more, to the action 
of natural selection in accumulating differ- 
ence of structure in certain definite direc- 
tions. Hence I believe a well-marked va- 
riety may be justly called an incipient 
species (p. 53). 
“Therefore, during the modification of the 
descendants of any one species, and during 
the incessant struggle of all species to in- 
crease in numbers, the more diversified 
their descendants become, the better will 
be their chance of succeeding in the battle 
of life. ‘Thus the small differences distin- 
guishing the varieties of the same species 
will steadily tend to increase till they come 
to equal the greater difference between 
species of the same genus, or even of distinct 
genera (p. 117). 
“Natural selection acts, as we have 
seen, exclusively by the preservation and 
accumulation of variations, which are 
beneficial under the organic and inorganic 
conditions of life to which each creature 
is at each successive period exposed’ 
(p. 117). 
As if to make the inadequacy of this 
conception more apparent, we have but 
to look back across the geological ages, 
or, accepting the law of recapitulation, 
to trace the embryonic development of a 
SCIENCE. 
[N. S. Vou. VI. No. 133. 
single higher animal, in order to discover 
that the earlier differentiations were of 
actually higher rank, and that as time has 
progressed the new forms of organisms 
have been restricted to modifications of 
less and less importance. The earlier in 
time we go the more fundamental were 
the variations which took place, and it is 
in later geological times that there has 
come to be more and more rigid adherence 
to the law of heredity. 
The proposed theory of original varia- 
bility is not only consistent with such a 
series of events, but they would be the 
natural expression of such a force in opera- 
tion. Variability should be most active 
and most vigorous before the laws of 
heredity had restricted its action. We 
must not, however, confuse activity of the 
operation of this law with multiplicity or 
complexity of activities in a common body. 
Complexity of structure is a matter of de- 
velopment and adjustment of the body it- 
self, and much collateral evolution would 
be necessary before it would be possible 
for great complexity in a single body to be 
consistent with the limits of its vital 
functions. That the changes and adjust- 
ments would be great and rapid in propor- 
tion to those that followed when the adjust- 
ments had become close and involved is, 
however, evident. Hence it would be con- 
sistent to expect rapid evolution at first, 
eradually decreasing in rate with advance 
of time, as paleontology teaches us to be- 
lieve was the actual fact of the case. 
The difficulty in the commonly accepted 
view, it seems to the author, arises from 
mental confusion rather than neglect of 
the real phenomenon in the case. The 
mental juggling takes place when we speak 
of varieties or variation becoming more 
permanent, or when we speak of the preser- 
vation and accumulation of variations. 
Variation as an act means becoming dif- 
ferent, but variation as a thing means 
