steemed of specific value: in some apricots the stone is almost
spherical, in others much flattened, being either sharp in front or
blunt at both ends, sometimes channelled along the back, or with a
sharp ridge along both margins. In the Moorpark, and generally in the
Hemskirke, the stone presents a singular character in being perforated,
with a bundle of fibres passing through the perforation from end to
end. The most constant and important character, according to Thompson,
is whether the kernel is bitter or sweet; yet in this respect we have a
graduated difference, for the kernel is very bitter in Shipley's
apricot; in the Hemskirke less bitter than in some other kinds;
slightly bitter in the Royal; and "sweet like a hazel-nut" in the
Breda, Angoumois, and others. In the case of the almond, bitterness has
been thought by some high authorities to indicate specific difference.

In N. America the Roman apricot endures "cold and unfavourable
situations, where no other sort, except the Masculine, will succeed;
and its blossoms bear quite a severe frost without injury."[682]
According to Mr. Rivers[683] seedling apricots deviate but little from
the character of {345} their race: in France the Alberge is constantly
reproduced from seed with but little variation. In Ladakh, according to
Moorcroft,[684] ten varieties of the apricot, very different from each
other, are cultivated, and all are raised from seed, excepting one,
which is budded.

[Illustration: Fig. 43.--Plum Stones, of natural size, viewed
laterally. 1. Bullace Plum. 2. Shropshire Damson. 3. Blue Gage. 4.
Orleans. 5. Elvas. 6. Denyer's Victoria. 7. Diamond.]

_Plums_ (_Prunus insititia_).--Formerly the sloe, _P. spinosa_, was
thought to be the parent of all our plums; but now this honour is very
commonly accorded to _P. insititia_ or the bullace, which is found wild
in the Caucasus and N.-Western India, and is naturalised in
England.[685] It is not at all improbable, in accordance with some
observations made by Mr. Rivers[686] that both these forms, which some
botanists rank as a single species, may be the parents of our
domesticated plums. Another supposed parent-form, the _P. domestica_,
is said to be found wild in the region of the Caucasus. Godron
remarks[687] that the cultivated varieties may be divided into two main
gro