he astonishing
waste of pollen by our fir trees; at the instinctive hatred of the queen
bee for her own fertile daughters; at ichneumonidae feeding within the
living bodies of caterpillars; or at other such cases. The wonder
indeed, is, on the theory of natural selection, that more cases of the
want of absolute perfection have not been detected.

The complex and little known laws governing production of varieties are
the same, as far as we can judge, with the laws which have governed the
production of distinct species. In both cases physical conditions seem
to have produced some direct and definite effect, but how much we cannot
say. Thus, when varieties enter any new station, they occasionally
assume some of the characters proper to the species of that station.
With both varieties and species, use and disuse seem to have produced a
considerable effect; for it is impossible to resist this conclusion when
we look, for instance, at the logger-headed duck, which has wings
incapable of flight, in nearly the same condition as in the domestic
duck; or when we look at the burrowing tucu-tucu, which is occasionally
blind, and then at certain moles, which are habitually blind and have
their eyes covered with skin; or when we look at the blind animals
inhabiting the dark caves of America and Europe. With varieties and
species, correlated variation seems to have played an important part, so
that when one part has been modified other parts have been necessarily
modified. With both varieties and species, reversions to long-lost
characters occasionally occur. How inexplicable on the theory of
creation is the occasional appearance of stripes on the shoulders and
legs of the several species of the horse-genus and of their hybrids! How
simply is this fact explained if we believe that these species are all
descended from a striped progenitor, in the same manner as the several
domestic breeds of the pigeon are descended from the blue and barred
rock pigeon!

On the ordinary view of each species having been independently created,
why should specific characters, or those by which the species of the
same genus differ from each other, be more variable than generic
characters in which they all agree? Why, for instance, should the colour
of a flower be more likely to vary in any one species of genus, if the
other species possess differently coloured flowers, than if all
possessed the same coloured flowers? If species are only well-marked
vari