No: 1-] ORGANIC VARIATION. 253 
Although the doctrine of Natural Selection will be but little 
mentioned in the following pages, it is nevertheless advisable 
to give a clear definition of it. Darwin states (“Origin of 
Species,’’new American edition from sixth English edition, 1886, 
p. 63) : ‘This preservation of favorable individual differences 
and variations, and the destruction of those which are injurious, 
I have called Natural Selection, or the Survival of the Fittest.” 
If we take this definition, and eliminate from it the sentence, 
‘‘and the destruction of those which are injurious,’ we have 
before us perhaps a true explanation of the origin of species. 
But the elimination of this passage seems necessary, since it is 
a debatable question to what extent the “destruction’’ of the 
unfavorable variations can proceed. Darwin himself discussed 
the preservation and destruction of variations, and left untouched 
the problem of their origin ; but in the “ Origin of Species”’ he 
makes two statements which are of interest here: “It seems 
clear that organic beings must be exposed during several gen- 
erations to new conditions to cause any great amount of varia- 
tion ; and that, when the organization has once begun to vary, 
it generally continues varying for many generations” (p. 5). 
«Unintentionally he [man] exposes organic beings to new and 
changing conditions of life, and variability ensues ; but similar 
changes of conditions might and do occur under nature ”’ (p. 62). 
From these two quotations we may conclude that Darwin con- 
sidered variation to have its origin in change of environment, — 
in which view he probably followed Lamarck. 
I. DEFINITION OF VARIATION ; CORRELATION OF ORGANS ; 
PROGRESSIVE AND REGRESSIVE DEVELOPMENT. 
Bateson applies the following definition to variation (/.c., p. 3) : 
“To this phenomenon, namely, the occurrence of differences 
between the structure, the instincts, or other elements which 
compose the mechanism of the offspring, and those which were 
proper to the parent, the name varzazzon has been given.” But 
since cases are known in which wholly normal offspring have 
descended from parents which were not normal in all respects, we 
cannot consider the offspring in such cases to present variations 
