Chapter X (2)

The cultivated species offer some variations worth notice. The Black
Prince, a seedling from Keen's Imperial (this latter being a seedling
of a very white strawberry, the white Carolina), is remarkable from
"its peculiar dark and polished surface, and from presenting an
appearance entirely unlike that of any other kind."[722] Although the
fruit in the different varieties differs so greatly in form, size,
colour, and quality, the so-called seed (which corresponds with the
whole fruit in the plum), with the exception of being more or less
deeply embedded in the pulp, is, according to De Jonghe,[723]
absolutely the same in all; and this no doubt may be accounted for by
the seed being of no value, and consequently not having been subjected
to selection. The strawberry is properly three-leaved, but in 1761
Duchesne raised a single-leaved variety of the European {353}
wood-strawberry, which Linnaeus doubtfully raised to the rank of a
species. Seedlings of this variety, like those of most varieties not
fixed by long-continued selection, often revert to the ordinary form,
or present intermediate states.[724] A variety raised by Mr.
Myatt,[725] apparently belonging to one of the American forms, presents
a variation of an opposite nature, for it has five leaves; Godron and
Lambertye also mention a five-leaved variety of _F. collina_.

The Red Bush Alpine strawberry (one of the _F. vesca_ section) does not
produce stolons or runners, and this remarkable deviation of structure
is reproduced truly by seed. Another sub-variety, the White Bush
Alpine, is similarly characterised, but when propagated by seed it
often degenerates and produces plants with runners.[726] A strawberry
of the American Pine section is also said to make but few runners.[727]

Much has been written on the sexes of strawberries; the true Hautbois
properly bears the male and female organs on separate plants,[728] and
was consequently named by Duchesne _dioica_; but it frequently produces
hermaphrodites; and Lindley,[729] by propagating such plants by
runners, at the same time destroying the males, soon raised a
self-prolific stock. The other species often show a tendency towards an
imperfect separation of the sexes, as I have noticed with plants forced
in a hot-house. Several English varieties, which in this country are
free from any such tendency, when cultivated in rich soils under the
climate of North America[730] commonly produce plants with separate
sexes. Thus a whole acre of Keen's Seedlings in the United States has
been observed to be almost sterile from the absence of male flowers;
but the more general rule is, that the male plants overrun the females.
Some members of the Cincinnati Horticultural Society, especially
appointed to investigate this subject, report that "few varieties have
the flowers perfect in both sexual organs," &c. The most successful
cultivators in Ohio, plant for every seven rows of "pistillata," or
female plants, one row of hermaphrodites, which afford pollen for both
kinds; but the hermaphrodites, owing to their expenditure in the
production of pollen, bear less fruit than the female plants.

The varieties differ in constitution. Some of our best English kinds,
such as Keen's Seedlings, are too tender for certain parts of North
America, where other English and many American varieties succeed
perfectly. That splendid fruit, the British Queen, can be cultivated
but in few places either in England or France; but this apparently
depends more on the nature of the soil than on the climate: a famous
gardener says that "no mortal could grow the British Queen at Shrubland
Park unless the whole nature of the soil was altered."[731] La
Constantina is one of the {354} hardiest kinds, and can withstand
Russian winters, but is easily burnt by the sun, so that it will not
succeed in certain soils either in England or the United States.[732]
The Filbert Pine Strawberry "requires more water than any other
variety; and if the plants once suffer from drought, they will do
little or no good afterwards."[733] Cuthill's Black Prince Strawberry
evinces a singular tendency to mildew: no less than six cases have been
recorded of this variety suffering severely, whilst other varieties
growing close by, and treated in exactly the same manner, were not at
all infested by this fungus.[734] The time of maturity differs much in
the different varieties; some belonging to the wood or alpine section
produce a succession of crops throughout the summer.

_Gooseberry_ (_Ribes grossularia_).--No one, I believe, has hitherto
doubted that all the cultivated kinds are sprung from the wild plant
bearing this name, which is common in Central and Northern Europe;
therefore it will be desirable briefly to specify all the points,
though not very important, which have varied. If it be admitted that
these differences are due to culture, authors perhaps will not be so
ready to assume the existence of a large number of unknown wild
parent-stocks for our other cultivated plants. The gooseberry is not
alluded to by writers of the classical period. Turner mentions it in
1573, and Parkinson, in 1629, specifies eight varieties; the Catalogue
of the Horticultural Society for 1842 gives 149 varieties, and the
lists of the Lancashire nurserymen are said to include above 300
names.[735] In the 'Gooseberry Grower's Register for 1862' I find that
243 distinct varieties have at various periods won prizes; so that a
vast number must have been exhibited. No doubt the difference between
many of the varieties is very small; but Mr. Thompson in classifying
the fruit for the Horticultural Society found less confusion in the
nomenclature of the gooseberry than of any other fruit, and he
attributes this "to the great interest which the prize-growers have
taken in detecting sorts with wrong names," and this shows that all the
kinds, numerous as they are, can be recognised with certainty.

The bushes differ in their manner of growth, being erect, or spreading,
or pendulous. The periods of leafing and flowering differ both
absolutely and relatively to each other; thus the Whitesmith produces
early flowers, which from not being protected by the foliage, as it is
believed, continually fail to produce fruit.[736] The leaves vary in
size, tint, and in depth of lobes; they are smooth, downy, or hairy on
the upper surface. The branches are more or less downy or spinose; "the
Hedgehog has probably derived its name from the singular bristly
condition of its shoots and fruit." The branches of the wild
gooseberry, I may remark, are smooth, with the exception of thorns at
the bases of the buds. The thorns themselves are either very small, few
and single, or very large and triple; they are {355} sometimes reflexed
and much dilated at their bases. In the different varieties the fruit
varies in abundance, in the period of maturity, in hanging until
shrivelled, and greatly in size, "some sorts having their fruit large
during a very early period of growth, whilst others are small until
nearly ripe." The fruit varies also much in colour, being red, yellow,
green, and white--the pulp of one dark-red gooseberry being tinged with
yellow; in flavour; in being smooth or downy,--few, however, of the Red
gooseberries, whilst many of the so-called Whites, are downy; or in
being so spinose that one kind is called Henderson's Porcupine. Two
kinds acquire when mature a powdery bloom on their fruit. The fruit
varies in the thickness and veining of the skin, and, lastly, in shape,
being spherical, oblong, oval, or obovate.[737]

I cultivated fifty-four varieties, and, considering how greatly the
fruit differs, it was curious how closely similar the flowers were in
all these kinds. In only a few I detected a trace of difference in the
size or colour of the corolla. The calyx differed in a rather greater
degree, for in some kinds it was much redder than in others; and in one
smooth white gooseberry it was unusually red. The calyx also differed
in the basal part being smooth or woolly, or covered with glandular
hairs. It deserves notice, as being contrary to what might have been
expected from the law of correlation, that a smooth red gooseberry had
a remarkably hairy calyx. The flowers of the Sportsman are furnished
with very large coloured bracteae; and this is the most singular
deviation of structure which I have observed. These same flowers also
varied much in the number of the petals, and occasionally in the number
of the stamens and pistils; so that they were semi-monstrous in
structure, yet they produced plenty of fruit. Mr. Thompson remarks that
in the Pastime gooseberry "extra bracts are often attached to the sides
of the fruit."[738]

The most interesting point in the history of the gooseberry is the
steady increase in the size of the fruit. Manchester is the metropolis
of the fanciers, and prizes from five shillings to five or ten pounds
are yearly given for the heaviest fruit. The 'Gooseberry Grower's
Register' is published annually; the earliest known copy is dated 1786,
but it is certain that meetings for the adjudication of prizes were
held some years previously.[739] The 'Register' for 1845 gives an
account of 171 Gooseberry Shows, held in different places during that
year; and this fact shows on how large a scale the culture has been
carried on. The fruit of the wild gooseberry is said[740] to weigh
about a quarter of an ounce or 5 dwts., that is, 120 grains; about the
year 1786 gooseberries were exhibited weighing 10 dwts., so that the
weight was then doubled; in 1817 26 dwts. 17 grs. was attained; there
was no advance till 1825, when 31 dwts. 16 grs. was reached; in {356}
1830 "Teazer" weighed 32 dwts. 13 grs.; in 1841 "Wonderful" weighed 32
dwts. 16 grs.; in 1844 "London" weighed 35 dwts. 12 grs., and in the
following year 36 dwts. 16 grs.; and in 1852 in Staffordshire the fruit
of this same variety reached the astonishing weight of 37 dwts. 7
grs.,[741] or 895 grs.; that is, between seven and eight times the
weight of the wild fruit. I find that a small apple, 61/2 inches in
circumference, has exactly this same weight. The "London" gooseberry
(which in 1862 had altogether gained 343 prizes) has, up to the present
year of 1864, never reached a greater weight than that attained in
1852. Perhaps the fruit of the gooseberry has now reached the greatest
possible weight, unless in the course of time some quite new and
distinct variety shall arise.

This gradual, and on the whole steady increase of weight from the
latter part of the last century to the year 1852, is probably in large
part due to improved methods of cultivation, for extreme care is now
taken; the branches and roots are trained, composts are made, the soil
is mulched, and only a few berries are left on each bush;[742] but the
increase no doubt is in main part due to the continued selection of
seedlings which have been found to be more and more capable of yielding
such extraordinary fruit. Assuredly the "Highwayman" in 1817 could not
have produced fruit like that of the "Roaring Lion" in 1825; nor could
the "Roaring Lion," though it was grown by many persons in many places,
gain the supreme triumph achieved in 1852 by the "London" Gooseberry.

_Walnut_ (_Juglans regia_).--This tree and the common nut belong to a
widely different order from the foregoing fruits, and are therefore
here noticed. The walnut grows wild in the Caucasus and Himalaya, where
Dr. Hooker[743] found the fruit of full size, but "as hard as a
hickory-nut." In England the walnut presents considerable differences,
in the shape and size of the fruit, in the thickness of the husk, and
in the thinness of the shell; this latter quality has given rise to a
variety called the thin-shelled, which is valuable, but suffers from
the attacks of tom-tits.[744] The degree to which the kernel fills the
shell varies much. In France there is a variety called the Grape or
cluster-walnut, in which the nuts grow in "bunches of ten, fifteen, or
even twenty together." There is another variety which bears on the same
tree differently shaped leaves, like the heterophyllous hornbeam; this
tree is also remarkable from having pendulous branches, and bearing
elongated, large, thin-shelled nuts.[745] M. Cardan has minutely
described[746] some singular physiological peculiarities in the
June-leafing variety, which produces its leaves and flowers four or
five weeks later, and retains its leaves and fruit in the autumn much
longer, than the common varieties; {357} but in August is in exactly
the same state with them. These constitutional peculiarities are
strictly inherited. Lastly, walnut-trees, which are properly monoicous,
sometimes entirely fail to produce male flowers.[747]

_Nuts_ (_Corylus avellana_).--Most botanists rank all the varieties
under the same species, the common wild nut.[748] The husk, or
involucre, differs greatly, being extremely short in Barr's Spanish,
and extremely long in filberts, in which it is contracted so as to
prevent the nut falling out. This kind of husk also protects the nut
from birds, for titmice (_Parus_) have been observed[749] to pass over
filberts, and attack cobs and common nuts growing in the same orchard.
In the purple-filbert the husk is purple, and in the frizzled-filbert
it is curiously laciniated; in the red-filbert the pellicle of the
kernel is red. The shell is thick in some varieties, but is thin in
Cosford's-nut, and in one variety is of a bluish colour. The nut itself
differs much in size and shape, being ovate and compressed in filberts,
nearly round and of great size in cobs and Spanish nuts, oblong and
longitudinally striated in Cosford's, and obtusely four-sided in the
Downton Square nut.

_Cucurbitaceous plants._--These plants have been for a long period the
opprobrium of botanists; numerous varieties have been ranked as
species, and, what happens more rarely, forms which now must be
considered as species have been classed as varieties. Owing to the
admirable experimental researches of a distinguished botanist, M.
Naudin,[750] a flood of light has recently been thrown on this group of
plants. M. Naudin, during many years, observed and experimented on
above 1200 living specimens, collected from all quarters of the world.
Six species are now recognised in the genus Cucurbita; but three alone
have been cultivated and concern us, namely, _C. maxima_ and _pepo_,
which include all pumpkins, gourds, squashes, and vegetable marrow, and
_C. moschata_, the water-melon. These three species are not known in a
wild state; but Asa Gray[751] gives good reason for believing that some
pumpkins are natives of N. America.

These three species are closely allied, and have the same general
habit, but their innumerable varieties can always be distinguished,
according to Naudin, by certain almost fixed characters; and what is
still more important, when crossed they yield no seed, or only sterile
seed; whilst the varieties spontaneously intercross with the utmost
freedom. Naudin insists strongly (p. 15), that, though these three
species have varied greatly in many characters, yet it has been in so
closely an analogous manner that the varieties can be arranged in
almost parallel series, as we have seen with the forms of wheat, with
the two main races of the peach, and in other cases. Though some of the
varieties are inconstant in character, yet others, when grown
separately under uniform conditions of life, are, as Naudin repeatedly
(pp. 6, 16, 35) urges, "douees d'une stabilite {358} presque comparable
a celle des especes les mieux caracterisees." One variety, l'Orangin
(pp. 43, 63), has such prepotency in transmitting its character that
when crossed with other varieties a vast majority of the seedlings come
true. Naudin, referring (p. 47) to _C. pepo_, says that its races "ne
different des especes veritables qu'en ce qu'elles peuvent s'allier les
unes aux autres par voie d'hybridite, sans que leur descendance perde
la faculte de se perpetuer." If we were to trust to external
differences alone, and give up the test of sterility, a multitude of
species would have to be formed out of the varieties of these three
species of Cucurbita. Many naturalists at the present day lay far too
little stress, in my opinion, on the test of sterility; yet it is not
improbable that distinct species of plants after a long course of
cultivation and variation may have their mutual sterility eliminated,
as we have every reason to believe has occurred with domesticated
animals. Nor, in the case of plants under cultivation, should we be
justified in assuming that varieties never acquire a slight degree of
mutual sterility, as we shall more fully see in a future chapter when
certain facts are given on the high authority of Gaertner and
Koelreuter.[752]

The forms of _C. pepo_ are classed by Naudin under seven sections, each
including subordinate varieties. He considers this plant as probably
the most variable in the world. The fruit of one variety (pp. 33, 46)
exceeds in volume that of another by more than two thousand fold! When
the fruit is of very large size, the number produced is few (p. 45);
when of small size, many are produced. No less astonishing (p. 33) is
the variation in the shape of the fruit; the typical form apparently is
egg-like, but this becomes either drawn out into a cylinder, or
shortened into a flat disc. We have also an almost infinite diversity
in the colour and state of surface of the fruit, in the hardness both
of the shell and of the flesh, and in the taste of the flesh, which is
either extremely sweet, farinaceous, or slightly bitter. The seeds also
differ in a slight degree in shape, and wonderfully in size (p. 34),
namely, from six or seven to more than twenty-five millimetres in
length.

In the varieties which grow upright or do not run and climb, the
tendrils, though useless (p. 31), are either present or are represented
by various semi-monstrous organs, or are quite absent. The tendrils are
even absent in some running varieties in which the stems are much
elongated. It is a singular fact that (p. 31), in all the varieties
with dwarfed stems, the leaves closely resemble each other in shape.

Those naturalists who believe in the immutability of species often
maintain that, even in the most variable forms, the characters which
they consider of specific value are unchangeable. To give an example
from a conscientious writer,[753] who, relying on the labours of M.
Naudin and {359} referring to the species of Cucurbita, says, "au
milieu de toutes les variations du fruit, les tiges, les feuilles, les
calices, les corolles, les etamines restent invariables dans chacune
d'elles." Yet M. Naudin in describing _Cucurbita pepo_ (p. 30) says,
"Ici, d'ailleurs, ce ne sont pas seulement les fruits qui varient,
c'est aussi le feuillage et tout le port de la plante. Neanmoins, je
crois qu'on la distinguera toujours facilement des deux autres especes,
si l'on veut ne pas perdre de vue les caracteres differentiels que je
m'efforce de faire ressortir. Ces caracteres sont quelquefois peu
marques: il arrive meme que plusieurs d'entre eux s'effacent presque
entierement, mais il en reste toujours quelques-uns qui remettent
l'observateur sur la voie." Now let it be noted what a difference, with
regard to the immutability of the so-called specific characters, this
paragraph produces on the mind, from that above quoted from M. Godron.

I will add another remark: naturalists continually assert that no
important organ varies; but in saying this they unconsciously argue in
a vicious circle; for if an organ, let it be what it may, is highly
variable, it is regarded as unimportant, and under a systematic point
of view this is quite correct. But as long as constancy is thus taken
as the criterion of importance, it will indeed be long before an
important organ can be shown to be inconstant. The enlarged form of the
stigmas, and their sessile position on the summit of the ovary, must be
considered as important characters, and were used by Gasparini to
separate certain pumpkins as a _distinct genus_; but Naudin says (p.
20) these parts have no constancy, and in the flowers of the Turban
varieties of _C. maxima_ they sometimes resume their ordinary
structure. Again, in _C. maxima_, the carpels (p. 19) which form the
Turban project even as much as two-thirds of their length out of the
receptacle, and this latter part is thus reduced to a sort of platform;
but this remarkable structure occurs only in certain varieties, and
graduates into the common form in which the carpels are almost entirely
enveloped within the receptacle. In _C. moschata_ the ovarium (p. 50)
varies greatly in shape, being oval, nearly spherical, or cylindrical,
more or less swollen in the upper part, or constricted round the
middle, and either straight or curved. When the ovarium is short and
oval the interior structure does not differ from that of _C. maxima_
and _pepo_, but when it is elongated the carpels occupy only the
terminal and swollen portion. I may add that in one variety of the
cucumber (_Cucumis sativus_) the fruit regularly contains five carpels
instead of three.[754] I presume that it will not be disputed that we
here have instances of great variability in organs of the highest
physiological importance, and with most plants of the highest
classificatory importance.

Sageret[755] and Naudin found that the cucumber (_C. sativus_) could
not be crossed with any other species of the genus; therefore no doubt
it is specifically distinct from the melon. This will appear to most
persons a superfluous statement; yet we hear from Naudin[756] that
there is a race {360} of melons, in which the fruit is so like that of
the cucumber, "both externally and internally, that it is hardly
possible to distinguish the one from the other except by the leaves."
The varieties of the melon seem to be endless, for Naudin after six
years' study has not come to the end of them: he divides them into ten
sections, including numerous sub-varieties which all intercross with
perfect ease.[757] Of the forms considered by Naudin to be varieties,
botanists have made thirty distinct species! "and they had not the
slightest acquaintance with the multitude of new forms which have
appeared since their time." Nor is the creation of so many species at
all surprising when we consider how strictly their characters are
transmitted by seed, and how wonderfully they differ in appearance:
"Mira est quidem foliorum et habitus diversitas, sed multo magis
fructuum," says Naudin. The fruit is the valuable part, and this, in
accordance with the common rule, is the most modified part. Some melons
are only as large as small plums, others weigh as much as sixty-six
pounds. One variety has a scarlet fruit! Another is not more than an
inch in diameter, but sometimes more than a yard in length, "twisting
about in all directions like a serpent." It is a singular fact that in
this latter variety many parts of the plant, namely, the stems, the
footstalks of the female flowers, the middle lobe of the leaves, and
especially the ovarium, as well as the mature fruit, all show a strong
tendency to become elongated. Several varieties of the melon are
interesting from assuming the characteristic features of distinct
species and even of distinct though allied genera: thus the
serpent-melon has some resemblance to the fruit of _Trichosanthes
anguina_; we have seen that other varieties closely resemble cucumbers;
some Egyptian varieties have their seeds attached to a portion of the
pulp, and this is characteristic of certain wild forms. Lastly, a
variety of melon from Algiers is remarkable from announcing its
maturity by "a spontaneous and almost sudden dislocation," when deep
cracks suddenly appear, and the fruit falls to pieces; and this occurs
with the wild _C. momordica_. Finally, M. Naudin well remarks that this
"extraordinary production of races and varieties by a single species,
and their permanence when not interfered with by crossing, are
phenomena well calculated to cause reflection."

USEFUL AND ORNAMENTAL TREES.

Trees deserve a passing notice on account of the numerous varieties
which they present, differing in their precocity, in their manner of
growth, foliage, and bark. Thus of the common ash (_Fraxinus
excelsior_) the catalogue of Messrs. Lawson of Edinburgh includes
twenty-one varieties, some of which differ much in their bark; there is
a yellow, a streaked reddish-white, a purple, a wart-barked and a
fungous-barked variety.[758] Of hollies no less than eighty-four
varieties are grown alongside each other in Mr. {361} Paul's
nursery.[759] In the case of trees, all the recorded varieties, as far
as I can find out, have been suddenly produced by one single act of
variation. The length of time required to raise many generations, and
the little value set on the fanciful varieties, explains how it is that
successive modifications have not been accumulated by selection; hence,
also it follows that we do not here meet with sub-varieties subordinate
to varieties, and these again subordinate to higher groups. On the
Continent, however, where the forests are more carefully attended to
than in England, Alph. De Candolle[760] says that there is not a
forester who does not search for seeds from that variety which he
esteems the most valuable.

Our useful trees have seldom been exposed to any great change of
conditions; they have not been richly manured, and the English kinds
grow under their proper climate. Yet in examining extensive beds of
seedlings in nursery-gardens considerable differences may be generally
observed in them; and whilst touring in England I have been surprised
at the amount of difference in the appearance of the same species in
our hedgerows and woods. But as plants vary so much in a truly wild
state, it would be difficult for even a skilful botanist to pronounce
whether, as I believe to be the case, hedgerow trees vary more than
those growing in a primeval forest. Trees when planted by man in woods
or hedges do not grow where they would naturally be able to hold their
place against a host of competitors, and are therefore exposed to
conditions not strictly natural: even this slight change would probably
suffice to cause seedlings raised from such trees to be variable.
Whether or not our half-wild English trees, as a general rule, are more
variable than trees growing in their native forests, there can hardly
be a doubt that they have yielded a greater number of strongly-marked
and singular variations of structure.

In manner of growth, we have weeping or pendulous varieties of the
willow, ash, elm, oak, and yew, and other trees; and this weeping habit
is sometimes inherited, though in a singularly capricious manner. In
the Lombardy poplar, and in certain fastigate or pyramidal varieties of
thorns, junipers, oaks, &c., we have an opposite kind of growth. The
Hessian oak,[761] which is famous from its fastigate habit and size,
bears hardly any resemblance in general appearance to a common oak;
"its acorns are not sure to produce plants of the same habit; some,
however, turn out the same as the parent-tree." Another fastigate oak
is said to have been found wild in the Pyrenees, and this is a
surprising circumstance; it generally comes so true by seed, that De
Candolle considered it as specifically distinct.[762] The fastigate
Juniper (_J. suecica_) likewise transmits its character by seed.[763]
Dr. Falconer informs me that in the Botanic Gardens at Calcutta the
great heat causes apple-trees to become fastigate; and we {362} thus
see the same result following from the effects of climate and from an
innate spontaneous tendency.[764]

In foliage we have variegated leaves which are often inherited; dark
purple or red leaves, as in the hazel, barberry, and beech, the colour
in these two latter trees being sometimes strongly and sometimes weakly
inherited;[765] deeply-cut leaves; and leaves covered with prickles, as
in the variety of the holly well called _ferox_, which is said to
reproduce itself by seed.[766] In fact, nearly all the peculiar
varieties evince a tendency, more or less strongly marked, to reproduce
themselves by seed.[767] This is to a certain extent the case,
according to Bose,[768] with three varieties of the elm, namely, the
broad-leafed, lime-leafed, and twisted elm, in which latter the fibres
of the wood are twisted. Even with the heterophyllous hornbeam
(_Carpinus betulus_), which bears on each twig leaves of two shapes,
"several plants raised from seed all retained the same
peculiarity."[769] I will add only one other remarkable case of
variation in foliage, namely, the occurrence of two sub-varieties of
the ash with simple instead of pinnated leaves, and which generally
transmit their character by seed.[770] The occurrence, in trees
belonging to widely different orders, of weeping and fastigate
varieties, and of trees bearing deeply cut, variegated, and purple
leaves, shows that these deviations of structure must result from some
very general physiological laws.

Differences in general appearance and foliage, not more strongly marked
than those above indicated, have led good observers to rank as distinct
species certain forms which are now known to be mere varieties. Thus a
plane-tree long cultivated in England was considered by almost every
one as a North American species; but is now ascertained by old records,
as I am informed by Dr. Hooker, to be a variety. So again the _Thuja
pendula_ or _filiformis_ was ranked by such good observers as Lambert,
Wallich, and others as a true species; but it is now known that the
original plants, five in number, suddenly appeared in a bed of
seedlings, raised at Mr. Loddige's nursery, from _T. orientalis_; and
Dr. Hooker has adduced excellent evidence that at Turin seeds of _T.
pendula_ have reproduced the parent-form, _T. orientalis_.[771]

Every one must have noticed how certain individual trees regularly put
forth and shed their leaves earlier or later than others of the same
species. There is a famous horse-chesnut in the Tuileries which is
named from {363} leafing so much earlier than the others. There is also
an oak near Edinburgh which retains its leaves to a very late period.
These differences have been attributed by some authors to the nature of
the soil in which the trees grow; but Archbishop Whately grafted an
early thorn on a late one, and _vice versa_, and both grafts kept to
their proper periods, which differed by about a fortnight, as if they
still grew on their own stocks.[772] There is a Cornish variety of the
elm which is almost an evergreen, and is so tender that the shoots are
often killed by the frost; and the varieties of the Turkish oak (_Q.
cerris_) may be arranged as deciduous, sub-evergreen, and
evergreen.[773]

_Scotch Fir_ (_Pinus sylvestris_).--I allude to this tree as it bears
on the question of the greater variability of our hedgerow trees
compared with those under strictly natural conditions. A well-informed
writer[774] states that the Scotch fir presents few varieties in its
native Scotch forests; but that it "varies much in figure and foliage,
and in the size, shape, and colour of its cones, when several
generations have been produced away from its native locality." There is
little doubt that the highland and lowland varieties differ in the
value of their timber, and that they can be propagated truly by seed;
thus justifying Loudon's remark, that "a variety is often of as much
importance as a species, and sometimes far more so."[775] I may mention
one rather important point in which this tree occasionally varies; in
the classification of the Coniferae, sections are founded on whether
two, three, or five leaves are included in the same sheath; the Scotch
fir has properly only two leaves thus enclosed, but specimens have been
observed with groups of three leaves in a sheath.[776] Besides these
differences in the semi-cultivated Scotch fir, there are in several
parts of Europe natural or geographical races, which have been ranked
by some authors as distinct species.[777] Loudon[778] considers _P.
pumilio_, with its several sub-varieties, as _Mughus_, _nana_, &c.,
which differ much when planted in different soils and only come
"tolerably true from seed," as alpine varieties of the Scotch fir; if
this were proved to be the case, it would be an interesting fact as
showing that dwarfing from long exposure to a severe climate is to a
certain extent inherited.

The _Hawthorn_ (_Crataegus oxycantha_) has varied much. Besides endless
slighter variations in the form of the leaves, and in the size,
hardness, fleshiness, and shape of the berries, Loudon[779] enumerates
twenty-nine well-marked varieties. Besides those cultivated for their
pretty flowers, there are others with golden-yellow, black, and whitish
berries; others {364} with woolly berries, and others with recurved
thorns. Loudon truly remarks that the chief reason why the hawthorn has
yielded more varieties than most other trees, is that curious
nurserymen select any remarkable variety out of the immense beds of
seedlings which are annually raised for making hedges. The flowers of
the hawthorn usually include from one to three pistils; but in two
varieties, named _Monogyna_ and _Sibirica_, there is only a single
pistil; and d'Asso states that the common thorn in Spain is constantly
in this state.[780] There is also a variety which is apetalous, or has
its petals reduced to mere rudiments. The famous Glastonbury thorn
flowers and leafs towards the end of December, at which time it bears
berries produced from an earlier crop of flowers.[781] It is worth
notice that several varieties of the hawthorn, as well as of the lime
and juniper, are very distinct in their foliage and habit whilst young,
but in the course of thirty or forty years become extremely like each
other;[782] thus reminding us of the well-known fact that the deodar,
the cedar of Lebanon, and that of the Atlas, are distinguished with the
greatest ease whilst young, but with difficulty when old.

FLOWERS.

I shall not for several reasons treat the variability of plants which
are cultivated for their flowers alone at any great length. Many of our
favourite kinds in their present state are the descendants of two or
more species crossed and commingled together, and this circumstance
alone would render it difficult to detect the differences due to
variation. For instance, our Roses, Petunias, Calceolarias, Fuchsias,
Verbenas, Gladioli, Pelargoniums, &c., certainly have had a multiple
origin. A botanist well acquainted with the parent-forms would probably
detect some curious structural differences in their crossed and
cultivated descendant; and he would certainly observe many new and
remarkable constitutional peculiarities. I will give a few instances,
all relating to the Pelargonium, and taken chiefly from Mr. Beck,[783]
a famous cultivator of this plant: some varieties require more water
than others; some are "very impatient of the knife if too greedily used
in making cuttings;" some, when potted, scarcely "show a root at the
outside of the ball of the earth;" one variety requires a certain
amount of confinement in the pot to make it throw up a flower-stem;
some varieties bloom well at the commencement of the season, others at
the close; one variety is known,[784] which will stand "even pine-apple
top and bottom heat, without looking any more drawn than if it had
stood in a common greenhouse; and Blanche Fleur seems as if made on
purpose for growing in winter, like many bulbs, and to rest all
summer." These odd constitutional peculiarities would fit a plant when
growing in a state of nature for widely different circumstances and
climates.

{365}

Flowers possess little interest under our present point of view,
because they have been almost exclusively attended to and selected for
their beautiful colours, size, perfect outline, and manner of growth.
In these particulars hardly one long-cultivated flower can be named
which has not varied greatly. What does a florist care for the shape
and structure of the organs of fructification, unless, indeed, they add
to the beauty of the flower? When this is the case, flowers become
modified in important points; stamens and pistils may be converted into
petals, and additional petals may be developed, as in all double
flowers. The process of gradual selection by which flowers have been
rendered more and more double, each step in the process of conversion
being inherited, has been recorded in several instances. In the
so-called double flowers of the Compositae, the corollas of the central
florets are greatly modified, and the modifications are likewise
inherited. In the columbine _(Aquilegia vulgaris)_ some of the stamens
are converted into petals having the shape of nectaries, one neatly
fitting into the other; but in one variety they are converted into
simple petals.[785] In the hose and hose primulae, the calyx becomes
brightly coloured and enlarged so as to resemble a corolla; and Mr. W.
Wooler informs me that this peculiarity is transmitted; for he crossed
a common polyanthus with one having a coloured calyx,[786] and some of
the seedlings inherited the coloured calyx during at least six
generations. In the "hen-and-chicken" daisy the main flower is
surrounded by a brood of small flowers developed from buds in the axils
of the scales of the involucre. A wonderful poppy has been described,
in which the stamens are converted into pistils; and so strictly was
this peculiarity inherited that, out of 154 seedlings, one alone
reverted to the ordinary and common type.[787] Of the cock's-comb
(_Celosia cristata_), which is an annual, there are several races in
which the flower-stem is wonderfully "fasciated" or compressed; and one
has been exhibited[788] actually eighteen inches in breadth. Peloric
races of _Gloxinia speciosa_ and _Antirrhinum majus_ can be propagated
by seed, and they differ in a wonderful manner from the typical form
both in structure and appearance.

A much more remarkable modification has been recorded by Sir William
and Dr. Hooker[789] in _Begonia frigida_. This plant properly produces
male and female flowers on the same fascicles; and in the female
flowers the perianth is superior; but a plant at Kew produced, besides
the ordinary flowers, others which graduated towards a perfect
hermaphrodite structure; and in these flowers the perianth was
inferior. To show the importance of this modification under a
classificatory point of view, I may quote what Prof. Harvey says,
namely, that had it "occurred in a state of nature, and had a botanist
collected a plant with such flowers, he would not only have {366}
placed it in a distinct genus from Begonia, but would probably have
considered it as the type of a new natural order." This modification
cannot in one sense be considered as a monstrosity, for analogous
structures naturally occur in other orders, as with Saxifragas and
Aristolochiaceae. The interest of the case is largely added to by Mr. C.
W. Crocker's observation that seedlings from the _normal_ flowers
produced plants which bore, in about the same proportion as the
parent-plant, hermaphrodite flowers having inferior perianths. The
hermaphrodite flowers fertilised with their own pollen were sterile.

If florists had attended to, selected, and propagated by seed other
modifications of structure besides those which are beautiful, a host of
curious varieties would certainly have been raised; and they would
probably have transmitted their characters so truly that the cultivator
would have felt aggrieved, as in the case of culinary vegetables, if
his whole bed had not presented a uniform appearance. Florists have
attended in some instances to the leaves of their plant, and have thus
produced the most elegant and symmetrical patterns of white, red, and
green, which, as in the case of the pelargonium, are sometimes strictly
inherited.[790] Any one who will habitually examine highly-cultivated
flowers in gardens and greenhouses will observe numerous deviations in
structure; but most of these must be ranked as mere monstrosities, and
are only so far interesting as showing how plastic the organisation
becomes under high cultivation. From this point of view such works as
Professor Moquin-Tandon's 'Teratologie' are highly instructive.

_Roses._--These flowers offer an instance of a number of forms
generally ranked as species, namely, _R. centifolia_, _gallica_,
_alba_, _damascena_, _spinosissima_, _bracteata_, _Indica_,
_semperflorens_, _moschata_, &c., which have largely varied and been
intercrossed. The genus Rosa is a notoriously difficult one, and,
though some of the above forms are admitted by all botanists to be
distinct species, others are doubtful; thus, with respect to the
British forms, Babington makes seventeen, and Bentham only five
species. The hybrids from some of the most distinct forms--for
instance, from _R. Indica_, fertilised by the pollen of _R.
centifolia_--produce an abundance of seed; I state this on the
authority of Mr. Rivers,[791] from whose work I have drawn most of the
following statements. As almost all the aboriginal forms brought from
different countries have been crossed and recrossed, it is no wonder
that Targioni-Tozzetti, in speaking of the common roses of the Italian
gardens, remarks that "the native country and precise form of the wild
type of most of them are involved in much uncertainty."[792]
Nevertheless Mr. Rivers in referring to _R. Indica_ (p. 68) says that
the descendants of each group may generally be recognised by a close
observer. The same author often speaks of roses as having been a little
hybridised; but {367} it is evident that in very many cases the
differences due to variation and to hybridisation can now only be
conjecturally distinguished.

The species have varied both by seed and by buds; such modified buds
being often called by gardeners sports. In the following chapter I
shall fully discuss this latter subject, and shall show that
bud-variations can be propagated not only by grafting and budding, but
often even by seed. Whenever a new rose appears with any peculiar
character, however produced, if it yields seed, Mr. Rivers (p. 4) fully
expects it to become the parent-type of a new family. The tendency to
vary is so strong in some kinds, as in the Village Maid (Rivers, p.
16), that when grown in different soils it varies so much in colour
that it has been thought to form several distinct kinds. Altogether the
number of kinds is very great: thus M. Desportes, in his Catalogue for
1829, enumerates 2562 as cultivated in France; but no doubt a large
proportion of these are merely nominal.

It would be useless to specify the many points of difference between
the various kinds, but some constitutional peculiarities may be
mentioned. Several French roses (Rivers, p. 12) will not succeed in
England; and an excellent horticulturist[793] remarks, that "Even in
the same garden you will find that a rose that will do nothing under a
south wall will do well under a north one. That is the case with Paul
Joseph here. It grows strongly and blooms beautifully close to a north
wall. For three years seven plants have done nothing under a south
wall." Many roses can be forced, "many are totally unfit for forcing,
among which is General Jacqueminot."[794] From the effects of crossing
and variation Mr. Rivers enthusiastically anticipates (p. 87) that the
day will come when all our roses, even moss-roses, will have evergreen
foliage, brilliant and fragrant flowers, and the habit of blooming from
June till November. "A distant view this seems, but perseverance in
gardening will yet achieve wonders," as assuredly it has already
achieved wonders.

It may be worth while briefly to give the well-known history of one
class of roses. In 1793 some wild Scotch roses (_R. spinosissima_) were
transplanted into a garden;[795] and one of these bore flowers slightly
tinged with red, from which a plant was raised with semi-monstrous
flowers, also tinged with red; seedlings from this flower were
semi-double, and by continued selection, in about nine or ten years,
eight sub-varieties were raised. In the course of less than twenty
years these double Scotch roses had so much increased in number and
kind, that twenty-six well-marked varieties, classed in eight sections,
were described by Mr. Sabine. In 1841[796] it is said that three
hundred varieties could be procured in the nursery-gardens near
Glasgow; and these are described as blush, crimson, purple, red,
marbled, two-coloured, white, and yellow, and as differing much in the
size and shape of the flower.

{368}

_Pansy or Heartsease_ (_Viola tricolor_, &c.).--The history of this
flower seems to be pretty well known; it was grown in Evelyn's garden
in 1687; but the varieties were not attended to till 1810-1812, when
Lady Monke, together with Mr. Lee the well-known nurseryman,
energetically commenced their culture; and in the course of a few years
twenty varieties could be purchased.[797] At about the same period,
namely in 1813 or 1814, Lord Gambier collected some wild plants, and
his gardener, Mr. Thomson, cultivated them together with some common
garden varieties, and soon effected a great improvement. The first
great change was the conversion of the dark lines in the centre of the
flower into a dark eye or centre, which at that period had never been
seen, but is now considered one of the chief requisites of a first-rate
flower. In 1835 a book entirely devoted to this flower was published,
and four hundred named varieties were on sale. From these circumstances
this plant seemed to me worth studying, more especially from the great
contrast between the small, dull, elongated, irregular flowers of the
wild pansy, and the beautiful, flat, symmetrical, circular, velvet-like
flowers, more than two inches in diameter, magnificently and variously
coloured, which are exhibited at our shows. But when I came to inquire
more closely, I found that, though the varieties were so modern, yet
that much confusion and doubt prevailed about their parentage. Florists
believe that the varieties[798] are descended from several wild stocks,
namely, _V. tricolor_, _lutea_, _grandiflora_, _amoena_, and _Altaica_,
more or less intercrossed. And when I looked to botanical works to
ascertain whether these forms ought to be ranked as species, I found
equal doubt and confusion. _Viola Altaica_ seems to be a distinct form,
but what part it has played in the origin of our varieties I know not;
it is said to have been crossed with _V. lutea_. _Viola amoena_[799] is
now looked at by all botanists as a natural variety of _V.
grandiflora_; and this and _V. sudetica_ have been proved to be
identical with _V. lutea_. The latter and _V. tricolor_ (including its
admitted variety _V. arvensis_) are ranked as distinct species by
Babington; and likewise by M. Gay,[800] who has paid particular
attention to the genus; but the specific distinction between _V. lutea_
and _tricolor_ is chiefly grounded on the one being strictly and the
other not strictly perennial, as well as on some other slight and
unimportant differences in the form of the stem and stipules. Bentham
unites these two forms; and a high authority on such matters, Mr. H. C.
Watson,[801] says that, "while _V. tricolor_ passes into _V. arvensis_
on the one side, it approximates so much towards _V. lutea_ and _V.
Curtisii_ on the other side, that a distinction becomes scarcely more
easy between them."

{369}

Hence, after having carefully compared numerous varieties, I gave up
the attempt as too difficult for any one except a professed botanist.
Most of the varieties present such inconstant characters, that when
grown in poor soil, or when flowering out of their proper season, they
produce differently coloured and much smaller flowers. Cultivators
speak of this or that kind as being remarkably constant or true; but by
this they do not mean, as in other cases, that the kind transmits its
character by seed, but that the individual plant does not change much
under culture. The principle of inheritance, however, does hold good to
a certain extent even with the fleeting varieties of the Heartease, for
to gain good sorts it is indispensable to sow the seed of good sorts.
Nevertheless in every large seed-bed a few almost wild seedlings often
reappear through reversion. On comparing the choicest varieties with
the nearest allied wild forms, besides the difference in the size,
outline, and colour of the flowers, the leaves are seen sometimes to
differ in shape, as does the calyx occasionally in the length and
breadth of the sepals. The differences in the form of the nectary more
especially deserve notice; because characters derived from this organ
have been much used in the discrimination of most of the species of
Viola. In a large number of flowers compared in 1842 I found that in
the greater number the nectary was straight; in others the extremity
was a little turned upwards, or downwards, or inwards, so as to be
completely hooked; in others, instead of being hooked, it was first
turned rectangularly downwards, and then backwards and upwards; in
others the extremity was considerably enlarged; and lastly, in some the
basal part was depressed, becoming, as usual, laterally compressed
towards the extremity. In a large number of flowers, on the other hand,
examined by me in 1856 from a nursery-garden in a different part of
England, the nectary hardly varied at all. Now M. Gay says that in
certain districts, especially in Auvergne, the nectary of the wild _V.
grandiflora_ varies in the manner just described. Must we conclude from
this that the cultivated varieties first mentioned were all descended
from _V. grandiflora_, and that the second lot, though having the same
general appearance, were descended from _V. tricolor_, of which the
nectary, according to M. Gay, is subject to little variation? Or is it
not more probable that both these wild forms would be found under other
conditions to vary in the same manner and degree, thus showing that
they ought not to be ranked as specifically distinct?

The _Dahlia_ has been referred to by almost every author who has
written on the variation of plants, because it is believed that all the
varieties are descended from a single species, and because all have
arisen since 1802 in France, and since 1804 in England.[802] Mr. Sabine
remarks that "it seems as if some period of cultivation had been
required before the fixed qualities of the native plant gave way and
began to sport into those changes which now so delight us."[803] The
flowers have been greatly modified in shape from a flat to a globular
form. Anemone and {370} ranunculus-like races,[804] which differ in the
form and arrangement of the florets, have arisen; also dwarfed races,
one of which is only eighteen inches in height. The seeds vary much in
size. The petals are uniformly coloured or tipped or striped, and
present an almost infinite diversity of tints. Seedlings of fourteen
different colours[805] have been raised from the same plant; yet, as
Mr. Sabine has remarked, "many of the seedlings follow their parents in
colour." The period of flowering has been considerably hastened, and
this has probably been effected by continued selection. Salisbury,
writing 1808, says that they then flowered from September to November;
in 1828 some new dwarf varieties began flowering in June;[806] and Mr.
Grieve informs me that the dwarf purple Zelinda in his garden is in
full bloom by the middle of June and sometimes even earlier. Slight
constitutional differences have been observed between certain
varieties: thus, some kinds succeed much better in one part of England
than in another;[807] and it has been noticed that some varieties
require much more moisture than others.[808]

Such flowers as the carnation, common tulip, and hyacinth, which are
believed to be descended, each from a single wild form, present
innumerable varieties, differing almost exclusively in the size, form,
and colour of the flowers. These and some other anciently cultivated
plants which have been long propagated by offsets, pipings, bulbs, &c.,
become so excessively variable, that almost each new plant raised from
seed forms a new variety, "all of which to describe particularly," as
old Gerarde wrote in 1597, "were to roll Sisyphus's stone, or to number
the sands."

_Hyacinth_ (_Hyacinthus orientalis_).--It may, however, be worth while
to give a short account of this plant, which was introduced into
England in 1596 from the Levant.[809] The petals of the original
flower, says Mr. Paul, were narrow, wrinkled, pointed, and of a flimsy
texture; now they are broad, smooth, solid, and rounded. The erectness,
breadth, and length of the whole spike, and the size of the flowers,
have all increased. The colours have been intensified and diversified.
Gerarde, in 1597, enumerates four, and Parkinson, in 1629, eight
varieties. Now the varieties are very numerous, and they were still
more numerous a century ago. Mr. Paul remarks that "it is interesting
to compare the Hyacinths of 1629 with those of 1864, and to mark the
improvement. Two hundred and thirty-five years have elapsed since then,
and this simple flower serves well to illustrate the great fact that
the original forms of nature do not remain fixed and stationary, at
least when brought under cultivation. While looking at the extremes, we
must not however forget that there are intermediate stages which are
for the most part lost to us. Nature will {371} sometimes indulge
herself with a leap, but as a rule her march is slow and gradual." He
adds that the cultivator should have "in his mind an ideal of beauty,
for the realisation of which he works with head and hand." We thus see
how clearly Mr. Paul, an eminently successful cultivator of this
flower, appreciates the action of methodical selection.