yellow variety, when fertilised by the white variety, yielded from seven
capsules an average of ninety-four seed. On the same principle, the white
variety of V. lychnitis by its own pollen (from six capsules), and by the
pollen of the yellow variety (eight capsules), yielded seed in the proportion
of 100 to 82. The yellow variety of V. thapsus by its own pollen (eight
capsules), and by that of the white variety (only two capsules), yielded seed
in the proportion of 100 to 94. Lastly, the white variety of V. blattaria by
its own pollen (eight capsules), and by that of the yellow variety (five
capsules), yielded seed in the proportion of 100 to 79. So that in every case
the unions of similarly-coloured varieties of the same species were more
fertile than the unions of dissimilarly-coloured varieties; when all the cases
are grouped together, the difference of fertility is as 100 to 86. Some
additional trials were made, and altogether thirty-six similarly-coloured
unions yielded thirty-five good capsules; whilst thirty-five dissimilarly-
coloured unions yielded only twenty-six good capsules. Besides the foregoing
experiments, the purple V. phoeniceum was crossed by a rose-coloured and a
white variety of the same species; these two varieties were also crossed
together, and these several unions yielded less seed than V. phoeniceum by its
own pollen. Hence it follows from Mr. Scott's experiments, that in the genus
Verbascum the similarly and dissimilarly-coloured varieties of the same
species behave, when crossed, like closely allied but distinct species.
(16/18. The following facts, given by Kolreuter in his 'Dritte Fortsetzung'
ss. 34, 39, appear at first sight strongly to confirm Mr. Scott's and
Gartner's statements; and to a certain limited extent they do so. Kolreuter
asserts, from innumerable observations, that insects incessantly carry pollen
from one species and variety of Verbascum to another; and I can confirm this
assertion; yet he found that the white and yellow varieties of Verbascum
lychnitis often grew wild mingled together: moreover, he cultivated these two
varieties in considerable numbers during four years in his garden, and they
kept true by seed; but when he crossed them, they produced flowers of an