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1859
1860
1861
1866
1869
1872

Compare with:
1859
1861
1866
1869
1872

possible), the rudimentary part would tend to be 1860 1861 1866
possible) the rudimentary part would tend to be 1859
OMIT 1869

economy, 1859 1860 1861
economy 1866
the economy of organisation, 1869

explained in 1859 1860 1861 1869
in organisation, explained in 1866

will probably often 1859 1860 1861 1866
may often have 1869

this will tend to cause 1859 1860 1861 1866
aided in 1869

7 blocks not present in 1859 1860 1861 1866 1869; present in 1872
There remains, however, this difficulty. After an organ has ceased being used, and has become in consequence much reduced, how can it be still further reduced in size until the merest vestige is left; and how can it be finally quite obliterated? It is scarcely possible that disuse can go on producing any further effect after the organ has once been rendered functionless. Some additional explanation is here requisite which I cannot give. If, for instance, it could be proved that every part of the organisation tends to vary in a greater degree towards diminution than towards augmentation of size, then we should be able to understand how an organ which has become useless would be rendered, independently of the effects of disuse, rudimentary and would at last be wholly suppressed; for the variations towards diminished size would no longer be checked by natural selection. The principle of the economy of growth, explained in a former chapter, by which the materials forming any part, if not useful to the possessor, are saved as far as is possible, will perhaps come into play in rendering a useless part rudimentary. But this principle will almost necessarily be confined to the earlier stages of the process of reduction; for we cannot suppose that a minute papilla, for instance, representing in a male flower the pistil of the female flower, and formed merely of cellular tissue, could be further reduced or absorbed for the sake of economising nutriment.

As the presence of 1859 1860 1861 1866 1869
Finally, as 1872

is thus due to the tendency in every part of the organisation, which has long existed, to be 1859 1860 1861 1866 1869
by whatever steps they may have been degraded into their present useless condition, are the record of a former state of things, and have been retained solely through the power of 1872

have 1859 1860 1861 1866 1869
in placing organisms in their proper places in the natural system, have often 1872

and can be accounted for by the laws of inheritance. 1859 1860 1861 1866
in accordance with the views here explained. 1869 1872

group to group in all organisms 1859 1860 1861
group to group in all organic beings 1866
all organic beings 1869 1872

that 1859 1860 1861 1866
in group under group— that 1869
in groups under groups— that 1872

into one grand system; 1859 1860 1861 1866
in a few grand classes,— 1869
into a few grand classes,— 1872

vital importance, or of 1859 1860 1861 1866
or 1869
or of 1872

to be possible), the rudimentary part would tend to be wholly lost, and we should have a case of complete abortion. The principle, also, of economy, explained in a former chapter, by which the materials forming any
part,
part
or structure,
or structure,
if not useful to the possessor, will be saved as far as is possible, will probably often come into
play,
play;
and this will tend to cause the entire obliteration of a rudimentary organ.
As the presence of rudimentary
organs,
organs
is thus due to the tendency in every part of the organisation, which has long existed, to be
inheritance,—
inherited—
we can understand, on the genealogical view of classification, how it is that
systematists,
systematists
have found rudimentary parts as useful as, or even sometimes more useful than, parts of high physiological importance. Rudimentary organs may be compared with the letters in a word, still retained in the spelling, but become useless in the pronunciation, but which serve as a clue
in seeking
in seeking
for its derivation. On the view of descent
with,
with
modification, we may conclude that the existence of organs in a rudimentary, imperfect, and useless condition, or quite aborted, far from presenting a strange difficulty, as they assuredly do on the
old
ordinary
doctrine of creation, might even have been
anticipated
anticipated,
and can be accounted for by the laws of inheritance.
Summary .
Summary .
Summary .—
In this chapter I have attempted to show, that the
arrangement
subordination
of group to group in all organisms throughout all
time
time;
that the nature of the
relationships
relationship,
by which all living and extinct
organisms
beings
are united by complex, radiating, and circuitous lines of affinities into one grand system; the rules followed and the difficulties encountered by naturalists in their
classifications,—
classifications;
the value set upon characters, if constant and prevalent, whether of high vital importance, or of the most trifling