Reviews and Extracts. — Horticulture., b^c. 113 
likely to produce a valuable variety, than if both sorts were selected I'lom one 
place; if a large apple is desired moderately sweet, select tw6 large apples for 
the purpose, the one as sweet as possible, the other acid. If a small variety is 
required, resort to two small ones for that purpose ; but in all otlier respects 
let dissimilarity be an invariable guide, both in flavour, habit, &c. 
"The power of i»-ucuring iiifermediate i',iripti"s, by the intermixture of the 
pollen and stigma of two dift'erent parents is, however, that which most deserves 
consideration. We all know that hybrid plants are constantly produced in every 
garden, and that improvenieats of the most remarkable kind, are yearly occurring 
inco;isequence. Experiments are, however, it may be sujiposed, sometimes made 
without the operator being exactly aware, either of the precise nature of the 
action, to which he is trusting for success, nr of the limits within which his expe- 
riments should be confined. 
•'Ci-oss-fertilization is eft'ected, as every one knows, by the action of the pollen 
of one plant upon the stigma of another. The nature of this action is highly 
curious. Pollen consists of extremely minute hollow balls or bodies; their cu\ity 
is filled with fluid, in which swim i)articles, of a figure varying from spherical to 
oblong, and having an apparently spoutancous motion. The stigma is composed 
of very lax tissue, the intercellular passages of which have a greater diameter 
than the moving particles of the pollen. 
<• When a grain of pollen comes in contact with the stigma, it bursts and dis- 
charges its contents among the lax tissue upon which it has fallen. The moving 
particles descend through the tissue of the style, until one or more of them, finds 
its way, by routes specially destined by nature for this service, into a little open- 
ing in the integuments of the ovulum, or young seed. Once deposited there, the 
particle swells, incieases gradually in size, separates into radicle and cotyledons, 
and finally becomes the embryo — that part which is to give birth, when the seed 
is sown, to a new individual. 
"Such being the mode in which the pollen influences the stigma, and subse- 
quently the seed, a practical consequence of great importance necessarily 
follows, viz. that in all cases of cross-fertilization, the new variety will take chiefly 
after its poliniferous, or male parent ; and that at the same time it will acquire 
some of the constitutional peculiarities of its mother.* Thus the n)ale parent of 
the Downton Strawberry, was the Old Black, the female, a kind of Scarlet; in 
Coe's Golden-drop Plum, the father was the Yellow Magnum Bonum, the mother 
the Green Gage ; and in the Elton Cherry, the White Heart was the male parent, 
and the Graffiouthe female. 
"The limits within which experiments of this kind must be confined are, how- 
ever, narrow. It seems that cross-fertilization will not take place at all, or very 
rarely, between different species, \inless these species are nearly related to each 
other; and that the oftspring of the two distinct species, is itself sterile, orif it 
possesses the power of multiplying itself by seed, its progeny returns back to the 
state of one or other of its parents. Hence it seldom or never has happened, that 
domesticated fruits have had such an origin. AVe have no varieties raised be- 
tween the Apple and the Pear, or the Quince and thelatter, or the Plum and 
Cherry, or the Gooseberry and Currant. On the other hand, new varieties, 
obtained by the intermixture of two pre-existing varieties, are not less prolific, 
but, on the contrary, often more so, than either of their parents ; witness the 
numerous sorts of Flemish Pears, which have been raised by cross-fertilization 
* In early cro.sses between distinct species, tliis is parfcularly m.inifest; t)ut in those of 
varieties lon^r (l<»>nesli<'ated, it is less apparent: the distiiirti las between tlie parents tbeni- 
selves I^eiiii;' less fixed, and le^?; clearly marked. 
VoL.l, No.;?. Q 
