| → quite recently Mr. 1859 1860 1861 |
| recently Sir J. 1866 1869 |
| Sir J. 1872 |
|
| → of an important part varying will ever be found: 1859 1860 1861 |
| will ever be found of an important part varying: 1866 1869 |
| will ever be found of an important part varying; 1872 |
|
| → seems to me 1859 1860 |
| is 1861 1866 1869 1872 |
|
| → hardly 1859 1860 1861 1866 |
| about which hardly 1869 |
| OMIT 1872 |
|
| → as species and which 1859 1860 1861 1866 |
| OMIT 1872 |
| them as species or 1869 |
|
| ↑ 1 blocks not present in 1859 1860 1861 1866 1869; present in 1872 |
| With respect to many of these forms, hardly two naturalists agree whether to rank them as species or as varieties.
|
|
| → and several genera of Brachiopod shells. 1859 1860 1861 |
| several genera of Brachiopod shells, and the Ruff (Machetes pugnax) amongst birds. 1866 1869 |
| and of Brachiopod shells. 1872 |
|
| → seem to be 1859 1860 |
| are 1861 1866 1869 1872 |
|
| → see in 1859 1860 1861 1866 |
| have at least in some of 1869 |
| see, at least in some of 1872 |
|
| → in points of structure 1859 1860 1861 1866 |
| OMIT 1869 1872 |
|
|
by slow
yet
→quite recently Mr.
Lubbock has shown a degree of variability in these main nerves in Coccus, which may almost be compared to the irregular branching of the stem of a tree. This philosophical naturalist, I may add, has also
shown that the muscles in the larvæ of certain insects are
far from uniform. Authors sometimes argue in a circle when they state that important organs never vary; for these same authors practically rank
as important (as some few naturalists have honestly confessed) which
not vary; and, under this point of view, no instance
→of an important part varying will ever be found:
but under any other point of view many instances assuredly can be given. |
|
| There is one point connected with individual differences, which
→seems to me
extremely perplexing: I refer to those genera which have
been called "protean" or "polymorphic," in which the species present an inordinate amount of
→hardly
→as species and which
↑
We may instance Rubus, Rosa, and Hieracium amongst plants, several genera of
→and several genera of Brachiopod shells. In most polymorphic genera some of the species have fixed and definite characters. Genera which are polymorphic in one country seem to be, with
few exceptions, polymorphic in other countries, and likewise, judging from Brachiopod shells, at former periods of time. These facts
→seem to be
very perplexing, for they seem to show that this kind of variability is independent of the conditions of life. I am inclined to suspect that we
→see in
these polymorphic
variations
→in points of structure
which are of no service or disservice to the species, and which consequently have not been seized on and rendered definite by natural selection, as hereafter
be explained.
|
