in accordance with the views of MM. Vilmorin and
Verlot,[891] is probably an attempt to revert to that uniform colour
which is natural to the species. A tulip, however, which has already
become broken, when treated with too strong manure, is liable to flush
or lose by a second act of reversion its variegated colours. Some
kinds, as Imperatrix Florum, are much more liable than others to
flushing; and Mr. Dickson maintains[892] that this can no more be
accounted for than the variation of any other plant. He believes that
English growers, from care in choosing seed from broken flowers instead
of from plain flowers, have to a certain extent diminished the tendency
in flowers already broken to flushing or secondary reversion.

During two consecutive years all the early flowers in a bed of
_Tigridia conchiflora_[893] resembled those of the old _T. pavonia_;
but the later flowers assumed their proper colour of fine yellow
spotted with crimson. An apparently authentic account has been
published[894] of two forms of Hemerocallis, which have been
universally considered as distinct species, changing into each other;
for the roots of the large-flowered tawny _H. fulva_, being divided and
planted in a different soil and place, produced the small-flowered
yellow _H. flava_, as well as some intermediate forms. It is doubtful
whether such cases as these latter, as well as the "flushing" of broken
tulips and the "running" of particoloured carnations,--that is, their
more or less complete return to a uniform tint,--ought to be classed
under bud-variation, or ought to be retained for the chapter in which I
treat of the direct action of the conditions of life on organic beings.
These cases, however, have this much in common with bud-variation, that
the change is effected through buds and not through seminal
reproduction. But, on the other hand, there is this difference--that in
ordinary cases of bud-variation, one bud alone changes, whilst in the
foregoing cases all the buds on the same plant were modified together;
yet we have an intermediate case, for with the potato all the eyes in
one tuber alone simultaneously changed their character.

I will conclude with a few allied cases, which may be ranked either
under bud-variation, or under the direct action of the conditions of
life. When the common Hepatica