between this principle and the theory of Natural Selection. 
We may first observe that Mr. Darwin admits that the 
phenomenon of correlated variation can take place apart 
from Natural Selection. 
“ We thus see that with plants many morphological changes may 
be attributed to the laws of growth and the interaction of parts 
independently of Natural Selection.'’—(Origin of Species, p. /75.) 
Mr. Darwin also asserts that those correlated variations 
which are useless cannot have been produced by Natural 
Selection. 
“ I know of no case better adapted to show the importance of the 
laws of correlation and variation independently of utility, and there 
fore of Natural Selection, than that of the difference between the 
outer and inner flowers in some Compositous and Umbelliferous 
plants.”—(Origin of Species, pp. /sj-6.) 
If this be so, it is clear that there is no department of 
organic life in which it is more necessary to examine the 
phenomena and to make ourselves quite sure as to the 
causes which initiate and carry out this change. If in 
some cases Natural Selection may have nothing to do with 
the phenomenon, and in other cases it cannot, we must not 
be too ready to identify the effect with this particular 
cause. 
But Mr. Darwin is not content to leave the matter 
thus. He says much in depreciation of the principle of 
correlated variation. It is very curious to observe that in 
his work on The Variation of Animals and Plants he 
begins the discussion of the subject by mentioning ex 
ceptions to the principle, or at any rate cases in which the 
principle seems to be in abeyance. 
“ All the parts of the organisation are to a certain extent connected 
or correlated together ; but the connection may be so slight that it 
hardly exists, as with compound animals or the buds on the same 
tree. Even in the higher animals various parts are not at all