Petite Mirabelle plum, yet this latter
kind (as well as the Quetsche) is known to have yielded some
well-established varieties; but, as Mr. Rivers remarks, they all belong
to the same group with the Mirabelle.

_Cherries (Prunus cerasus, avium_, &c.).--Botanists believe that our
cultivated cherries are descended from one, two, four, or even more
wild stocks.[692] That there must be at least two parent-species we may
infer from the sterility of twenty hybrids raised by Mr. Knight from
the morello fertilized by pollen of the Elton cherry; for these hybrids
produced in all only five cherries, and one alone of these contained a
seed.[693] Mr. Thompson[694] has classified the varieties in an
apparently natural method in two main groups by characters taken from
the flowers, fruit, and leaves; but some varieties which stand widely
separate in this classification are quite fertile when crossed; thus
Knight's Early Black cherry is the product of a cross between two such
kinds.

Mr. Knight states that seedling cherries are more variable than those
of any other fruit-tree.[695] In the Catalogue of the Horticultural
Society for 1842, eighty varieties are enumerated. Some varieties
present singular characters: thus the flower of the Cluster cherry
includes as many as twelve pistils, of which the majority abort; and
they are said generally to produce from two to five or six cherries
aggregated together and borne on a single peduncle. In the Ratafia
cherry several flower-peduncles arise from a common peduncle, upwards
of an inch in length. The fruit of Gascoigne's Heart has its apex
produced into a globule or drop: that of the white {348} Hungarian Gean
has almost transparent flesh. The Flemish cherry is "a very odd-looking
fruit," much flattened at the summit and base, with the latter deeply
furrowed, and borne on a stout very short footstalk. In the Kentish
cherry the stone adheres so firmly to the footstalk, that it can be
drawn out of the flesh; and this renders the fruit well fitted for
drying. The Tobacco-leaved cherry, according to Sageret and Thompson,
produces gigantic leaves, more than a foot and sometimes even eighteen
inches in length, and half a foot in breadth. The Weeping cherry, on
the other hand, is valuable only as an ornament, and, according to
Downing, is "a charming little tr