young plants contracted an adhesion to the supporting tree. Some of the
instances recorded by classical writers may be attributed to intentional
or accidental fallacy, as in the so-called "greffe des charlatans" of
more modern days.

Adhesion of the roots of different species has been effected
artificially, as between the carrot and the beet root, while Dr. Maclean
succeeded in engrafting, on a red beet, a scion of the white Silesian
variety of the same species. In all these cases, even in the most
successful grafts, the amount of adhesion is very slight; the union in
no degree warrants the term fusion, it is little but simple contact of
similar tissues, while new growing matter is formed all round the cut
surfaces, so that the latter become gradually imbedded in the newly
formed matter.

=Synophty or adhesion of the embryo.=--This often occurs partially in
the embryo plants of the common mistleto (_Viscum_), but is not of
common occurrence in other plants, even in such cases as the orange
(_Citrus_), the _Cycadeae_, _Coniferae_, &c., where there is frequently
more than one embryo in the seed. Alphonse De Candolle has described and
figured an instance of the kind in _Euphorbia helioscopia_, wherein two
embryo plants were completely grafted together throughout the whole
length of their axes, leaving merely the four cotyledons separate. A
similar adnation has been observed by the same botanist in _Lepidium
sativum_ and _Sinapis ramosa_, as well as in other plants.[64] I have
met with corresponding instances in _Antirrhinum majus_ and in _Crataegus
oxyacantha_, in the latter case complicated with the partial atrophy of
one of the four cotyledons. It is necessary to distinguish between such
cases and the fallacious appearances arising from a division of the
cotyledons. M. Morren has figured and described the union of two roots
of carrot (_Daucus_), which were also spirally twisted. He attributes
this union to the blending of two radicles, and applies the term
"rhizocollesy" to this union of the roots.[65] Mr. Thwaites cites a case
wherein two embryos were contained in one seed in a _Fuchsia_, and had
become adherent. What is still more remarkable, the two embryos were
different, a circumstance attributable to their hybrid origin, the seed
containing them being the result of the fertilisation of _Fuchsia
coccinea_ (quere _F. magellanica?_) by the pollen of _F. fulgens_.

FOOTNOTES:

[30] Wydler, 'Flora,' 1852, p. 737,