eral years ago he
cut about sixty blue and white potatoes into halves through the eyes or
buds, and then carefully joined them, destroying at the same time the
other eyes. Some of these united tubers produced white, and others blue
tubers; and it is probable that in these cases the one half alone of
the bud grew. Some, however, produced tubers partly white and partly
blue; and the tubers from about four or five were regularly mottled
with the two colours. in these latter cases we may conclude that a stem
had been formed by {396} the union of the bisected buds; and as tubers
are produced by the enlargement of subterranean branches arising from
the main stem, their mottled colour apparently affords clear evidence
of the intimate commingling of the two varieties. I have repeated these
experiments on the potato and on the hyacinth on a large scale, but
with no success.

The most reliable instance known to me of the formation of a
graft-hybrid is one, recorded by Mr. Poynter,[927] who assures me, in a
letter of the entire accuracy of the statement, _Rosa Devoniensis_ had
been budded some years previously on a white Banksian rose; and from
the much enlarged point of junction, whence the Devoniensis and
Banksian still continued to grow, a third branch issued, which was
neither pure Banksian nor pure Devoniensis, but partook of the
character of both; the flowers resembled, but were superior in
character to those of the variety called _Lamarque_ (one of the
Noisettes), while the shoots were similar in their manner of growth to
those of the Banksian rose, with the exception that the longer and more
robust shoots were furnished with prickles. This rose was exhibited
before the Floral Committee of the Horticultural Society of London. Dr.
Lindley examined it, and concluded that it had certainly been produced
by the mingling of _R. Banksiae_ with some rose like _R. Devoniensis_,
"for while it was very greatly increased in vigour and in the size of
all the parts, the leaves were half-way between a Banksian and
Tea-scented rose." It appears that rose-growers were aware that the
Banksian rose sometimes affects other roses. Had it not been for this
latter statement, it might have been suspected that this new variety
was simply due to bud-variation, and that it had occurred by a mere
accident at the po