CULTIVATED PLANTS: CEREAL AND CULINARY PLANTS.
PRELIMINARY REMARKS ON THE NUMBER AND PARENTAGE OF CULTIVATED PLANTS.
FIRST STEPS IN CULTIVATION.
GEOGRAPHICAL DISTRIBUTION OF CULTIVATED PLANTS.
CEREALIA.
DOUBTS ON THE NUMBER OF SPECIES.
WHEAT: VARIETIES OF.
INDIVIDUAL VARIABILITY.
CHANGED HABITS.
SELECTION.
ANCIENT HISTORY OF THE VARIETIES.
MAIZE: GREAT VARIATION OF.
DIRECT ACTION OF CLIMATE ON.
CULINARY PLANTS.
CABBAGES: VARIETIES OF, IN FOLIAGE AND STEMS, BUT NOT IN OTHER PARTS.
PARENTAGE OF.
OTHER SPECIES OF BRASSICA.
PEAS: AMOUNT OF DIFFERENCE IN THE SEVERAL KINDS, CHIEFLY IN THE PODS AND
SEED.
SOME VARIETIES CONSTANT, SOME HIGHLY VARIABLE.
DO NOT INTERCROSS.
BEANS.
POTATOES: NUMEROUS VARIETIES OF.
DIFFERING LITTLE EXCEPT IN THE TUBERS.
CHARACTERS INHERITED.
I shall not enter into so much detail on the variability of cultivated
plants, as in the case of domesticated animals. The subject is involved in
much difficulty. Botanists have generally neglected cultivated varieties,
as beneath their notice. In several cases the wild prototype is unknown or
doubtfully known; and in other cases it is hardly possible to distinguish
between escaped seedlings and truly wild plants, so that there is no safe
standard of comparison by which to judge of any supposed amount of change.
Not a few botanists believe that several of our anciently cultivated plants
have become so profoundly modified that it is not possible now to recognise
their aboriginal parent-forms. Equally perplexing are the doubts whether
some of them are descended from one species, or from several inextricably
commingled by crossing and variation. Variations often pass into, and
cannot be distinguished from, monstrosities; and monstrosities are of
little significance for our purpose. Many varieties are propagated solely
by grafts, buds, layers, bulbs, etc., and frequently it is not known how
far their peculiarities can be transmitted by seminal generation.
Nevertheless, some facts of value can be gleaned: and other facts will
hereafter be incidentally given. One chief object in the two following
chapters is to show how many characters in our cultivated plants have
become variable.
Before entering on details a few general remarks on the origin of
cultivated plants may be introduced. M. Alph. De Candolle (9/1. 'Geographie
botanique raisonnee' 1855 pages 810 to 991.) in an admirable discussion on
this subject, in which he displays a wonderful amount of knowledge, gives a
list of 157 of the most useful cultivated plants. Of these he believes that
85 are almost certainly known in their wild state; but on this head other
competent judges (9/2. Review by Mr. Bentham in 'Hort. Journal' volume 9
1855 page 133 entitled 'Historical Notes on cultivated Plants' by Dr. A.
Targioni-Tozzetti. See also 'Edinburgh Review' 1866 page 510.) entertain
great doubts. Of 40 of them, the origin is admitted by M. De Candolle to be
doubtful, either from a certain amount of dissimilarity which they present
when compared with their nearest allies in a wild state, or from the
probability of the latter not being truly wild plants, but seedlings
escaped from culture. Of the entire 157, 32 alone are ranked by M. De
Candolle as quite unknown in their aboriginal condition. But it should be
observed that he does not include in his list several plants which present
ill-defined characters, namely, the various forms of pumpkins, millet,
sorghum, kidney-bean, dolichos, capsicum, and indigo. Nor does he include
flowers; and several of the more anciently cultivated flowers, such as
certain roses, the common Imperial lily, the tuberose, and even the lilac,
are said (9/3. 'Hist. Notes' as above by Targioni-Tozzetti.) not to be
known in the wild state.
From the relative numbers above given, and from other arguments of much
weight, M. De Candolle concludes that plants have rarely been so much
modified by culture that they cannot be identified with their wild
prototypes. But on this view, considering that savages probably would not
have chosen rare plants for cultivation, that useful plants are generally
conspicuous, and that they could not have been the inhabitants of deserts
or of remote and recently discovered islands, it appears strange to me that
so many of our cultivated plants should be still unknown or only doubtfully
known in the wild state. If, on the other hand, many of these plants have
been profoundly modified by culture, the difficulty disappears. The
difficulty would also be removed if they have been exterminated during the
progress of civilisation; but M. De Candolle has shown that this probably
has seldom occurred. As soon as a plant was cultivated in any country, the
half-civilised inhabitants would no longer have need to search the whole
surface of the land for it, and thus lead to its extirpation; and even if
this did occur during a famine, dormant seeds would be left in the ground.
In tropical countries the wild luxuriance of nature, as was long ago
remarked by Humboldt, overpowers the feeble efforts of man. In anciently
civilised temperate countries, where the whole face of the land has been
greatly changed, it can hardly be doubted that some plants have become
extinct; nevertheless De Candolle has shown that all the plants
historically known to have been first cultivated in Europe still exist here
in the wild state.
MM. Loiseleur-Deslongchamps (9/4. 'Considerations sur les Cereales' 1842
page 37. 'Geographie Bot.' 1855 page 930. "Plus on suppose l'agriculture
ancienne et remontant a une epoque d'ignorance, plus il est probable que
les cultivateurs avaient choisi des especes offrant a l'origine meme un
avantage incontestable.") and De Candolle have remarked that our cultivated
plants, more especially the cereals, must originally have existed in nearly
their present state; for otherwise they would not have been noticed and
valued as objects of food. But these authors apparently have not considered
the many accounts given by travellers of the wretched food collected by
savages. I have read an account of the savages of Australia cooking, during
a dearth, many vegetables in various ways, in the hopes of rendering them
innocuous and more nutritious. Dr. Hooker found the half-starved
inhabitants of a village in Sikhim suffering greatly from having eaten
arum-roots (9/5. Dr. Hooker has given me this information. See also his
'Himalayan Journals' 1854 volume 2 page 49.), which they had pounded and
left for several days to ferment, so as partially to destroy their
poisonous nature; and he adds that they cooked and ate many other
deleterious plants. Sir Andrew Smith informs me that in South Africa a
large number of fruits and succulent leaves, and especially roots, are used
in times of scarcity. The natives, indeed, know the properties of a long
catalogue of plants, some having been found during famines to be eatable,
others injurious to health, or even destructive to life. He met a party of
Baquanas who, having been expelled by the conquering Zulus, had lived for
years on any roots or leaves which afforded some little nutriment and
distended their stomachs, so as to relieve the pangs of hunger. They looked
like walking skeletons, and suffered fearfully from constipation. Sir
Andrew Smith also informs me that on such occasions the natives observe as
a guide for themselves, what the wild animals, especially baboons and
monkeys, eat.
From innumerable experiments made through dire necessity by the savages of
every land, with the results handed down by tradition, the nutritious,
stimulating, and medicinal properties of the most unpromising plants were
probably first discovered. It appears, for instance, at first an
inexplicable fact that untutored man, in three distant quarters of the
world, should have discovered, amongst a host of native plants, that the
leaves of the tea-plant and mattee, and the berries of the coffee, all
included a stimulating and nutritious essence, now known to be chemically
the same. We can also see that savages suffering from severe constipation
would naturally observe whether any of the roots which they devoured acted
as aperients. We probably owe our knowledge of the uses of almost all
plants to man having originally existed in a barbarous state, and having
been often compelled by severe want to try as food almost everything which
he could chew and swallow.
From what we know of the habits of savages in many quarters of the world,
there is no reason to suppose that our cereal plants originally existed in
their present state so valuable to man. Let us look to one continent alone,
namely, Africa: Barth (9/6. 'Travels in Central Africa' English translation
volume 1 pages 529 and 390; volume 2 pages 29, 265, 270. Livingstone
'Travels' page 551.) states that the slaves over a large part of the
central region regularly collect the seeds of a wild grass, the Pennisetum
distichum; in another district he saw women collecting the seeds of a Poa
by swinging a sort of basket through the rich meadow-land. Near Tete,
Livingstone observed the natives collecting the seeds of a wild grass, and
farther south, as Andersson informs me, the natives largely use the seed of
a grass of about the size of canary-seed, which they boil in water. They
eat also the roots of certain reeds, and every one has read of the Bushmen
prowling about and digging up with a fire-hardened stake various roots.
Similar facts with respect to the collection of seeds of wild grasses in
other parts of the world could be given. (9/7. For instance in both North
and South America. Mr. Edgeworth 'Journal Proc. Linn. Soc.' vol 6 Bot. 1862
page 181 states that in the deserts of the Punjab poor women sweep up, "by
a whisk into straw baskets," the seeds of four genera of grasses, namely,
of Agrostis, Panicum, Cenchrus, and Pennisetum, as well as the seeds of
four other genera belonging to distinct families.)
Accustomed as we are to our excellent vegetables and luscious fruits, we
can hardly persuade ourselves that the stringy roots of the wild carrot and
parsnip, or the little shoots of the wild asparagus, or crabs, sloes, etc.,
should ever have been valued; yet, from what we know of the habits of
Australian and South African savages, we need feel no doubt on this head.
The inhabitants of Switzerland during the Stone-period largely collected
wild crabs, sloes, bullaces, hips of roses, elderberries, beechmast, and
other wild berries and fruit. (9/8. Prof. O. Heer 'Die Pflanzen der
Pfahlbauten' 1866 aus dem Neujahr. Naturforsch. Geselschaft' 1866; and Dr.
H. Christ in Rutimeyer's 'Die Fauna der Pfahlbauten' 1861 s. 226.) Jemmy
Button, a Fuegian on board the 'Beagle,' remarked to me that the poor and
acid black-currants of Tierra del Fuego were too sweet for his taste.
The savage inhabitants of each land, having found out by many and hard
trials what plants were useful, or could be rendered useful by various
cooking processes, would after a time take the first step in cultivation by
planting them near their usual abodes. Livingstone (9/9. 'Travels' page
535. Du Chaillu 'Adventures in Equatorial Africa' 1861 page 445.) states
that the savage Batokas sometimes left wild fruit-trees standing in their
gardens, and occasionally even planted them, "a practice seen nowhere else
amongst the natives." But Du Chaillu saw a palm and some other wild fruit-
trees which had been planted; and these trees were considered private
property. The next step in cultivation, and this would require but little
forethought, would be to sow the seeds of useful plants; and as the soil
near the hovels of the natives (9/10. In Tierra del Fuego the spot where
wigwams had formerly stood could be distinguished at a great distance by
the bright green tint of the native vegetation.) would often be in some
degree manured, improved varieties would sooner or later arise. Or a wild
and unusually good variety of a native plant might attract the attention of
some wise old savage; and he would transplant it, or sow its seed. That
superior varieties of wild fruit-trees occasionally are found is certain,
as in the case of the American species of hawthorns, plums, cherries,
grapes, and hickories, specified by Professor Asa Gray. (9/11. 'American
Acad. of Arts and Sciences' April 10th, 1860 page 413. Downing 'The Fruits
of America' 1845 page 261.) Downing also refers to certain wild varieties
of the hickory, as being "of much larger size and finer flavour than the
common species." I have referred to American fruit-trees, because we are
not in this case troubled with doubts whether or not the varieties are
seedlings which have escaped from cultivation. Transplanting any superior
variety, or sowing its seeds, hardly implies more forethought than might be
expected at an early and rude period of civilisation. Even the Australian
barbarians "have a law that no plant bearing seeds is to be dug up after it
has flowered;" and Sir G. Grey (9/12. 'Journals of Expeditions in
Australia' 1841 volume 2 page 292.) never saw this law, evidently framed
for the preservation of the plant, violated. We see the same spirit in the
superstitious belief of the Fuegians, that killing water-fowl whilst very
young will be followed by "much rain, snow, blow much." (9/13. Darwin
'Journal of Researches' 1845 page 215.) I may add, as showing forethought
in the lowest barbarians, that the Fuegians when they find a stranded whale
bury large portions in the sand, and during the often-recurrent famines
travel from great distances for the remnants of the half-putrid mass.
It has often been remarked (9/14. De Candolle has tabulated the facts in
the most interesting manner in his 'Geographie Bot.' page 986.) that we do
not owe a single useful plant to Australia or the Cape of Good Hope,
countries abounding to an unparalleled degree with endemic species,--or to
New Zealand, or to America south of the Plata; and, according to some
authors, not to America northward of Mexico. I do not believe that any
edible or valuable plant, except the canary-grass, has been derived from an
oceanic or uninhabited island. If nearly all our useful plants, natives of
Europe; Asia, and South America, had originally existed in their present
condition, the complete absence of similarly useful plants in the great
countries just named would be indeed a surprising fact. But if these plants
have been so greatly modified and improved by culture as no longer closely
to resemble any natural species, we can understand why the above-named
countries have given us no useful plants, for they were either inhabited by
men who did not cultivate the ground at all, as in Australia and the Cape
of Good Hope, or who cultivated it very imperfectly, as in some parts of
America. These countries do yield plants which are useful to savage man;
and Dr. Hooker (9/15. 'Flora of Australia' Introduction page 110.)
enumerates no less than 107 such species in Australia alone; but these
plants have not been improved, and consequently cannot compete with those
which have been cultivated and improved during thousands of years in the
civilised world.
The case of New Zealand, to which fine island we as yet owe no widely
cultivated plant, may seem opposed to this view; for, when first
discovered, the natives cultivated several plants; but all inquirers
believe, in accordance with the traditions of the natives, that the early
Polynesian colonists brought with them seeds and roots, as well as the dog,
which had been wisely preserved during their long voyage. The Polynesians
are so frequently lost on the ocean that this degree of prudence would
occur to any wandering party: hence the early colonists of New Zealand,
like the later European colonists, would not have had any strong inducement
to cultivate the aboriginal plants. According to De Candolle we owe thirty-
three useful plants to Mexico, Peru, and Chile; nor is this surprising when
we remember the civilised state of the inhabitants, as shown by the fact of
their having practised artificial irrigation and made tunnels through hard
rocks without the use of iron or gunpowder, and who, as we shall see in a
future chapter, fully recognised, as far as animals were concerned, and
therefore probably in the case of plants, the important principle of
selection. We owe some plants to Brazil; and the early voyagers, namely,
Vespucius and Cabral, describe the country as thickly peopled and
cultivated. In North America (9/16. For Canada see J. Cartier's Voyage in
1534; for Florida see Narvaez and Ferdinand de Soto's Voyages. As I have
consulted these and other old Voyages in more than one general collection
of Voyages, I do not give precise references to the pages. See also for
several references Asa Gray in the 'American Journal of Science' volume 24
November 1857 page 441. For the traditions of the natives of New Zealand
see Crawfurd 'Grammar and Dict. of the Malay Language' 1852 page 260.) the
natives cultivated maize, pumpkins, gourds, beans, and peas, "all different
from ours," and tobacco; and we are hardly justified in assuming that none
of our present plants are descended from these North American forms. Had
North America been civilised for as long a period, and as thickly peopled,
as Asia or Europe, it is probable that the native vines, walnuts,
mulberries, crabs, and plums, would have given rise, after a long course of
cultivation, to a multitude of varieties, some extremely different from
their parent-stocks; and escaped seedlings would have caused in the New, as
in the Old World, much perplexity with respect to their specific
distinctness and parentage.' (9/17. See for example Mr. Hewett C. Watson's
remarks on our wild plums and cherries and crabs: 'Cybele Britannica'
volume 1 pages 330, 334, etc. Van Mons (in his 'Arbres Fruitiers' 1835 tome
1 page 444) declares that he has found the types of all our cultivated
varieties in wild seedlings, but then he looks on these seedlings as so
many aboriginal stocks.)
[CEREALIA.
I will now enter on details. The cereals cultivated in Europe consist of
four genera--wheat, rye, barley, and oats. Of wheat the best modern
authorities (9/18. See A. De Candolle 'Geograph. Bot.' 1855 page 928 et
seq. Godron 'De l'Espece' 1859 tome 2 page 70; and Metzger 'Die
Getreidearten' etc. 1841.) make four or five, or even seven distinct
species; of rye, one; of barley, three; and of oats, two, three, or four
species. So that altogether our cereals are ranked by different authors
under from ten to fifteen distinct species. These have given rise to a
multitude of varieties. It is a remarkable fact that botanists are not
universally agreed on the aboriginal parent-form of any one cereal plant.
For instance, a high authority writes in 1855 (9/19. Mr. Bentham in his
review entitled 'Hist. Notes on cultivated Plants' by Dr. A. Targioni-
Tozzetti in 'Journal of Hort. Soc.' volume 9 1855 page 133. He informs me
that he still retains the same opinion.), "We ourselves have no hesitation
in stating our conviction, as the result of all the most reliable evidence,
that none of these Cerealia exist, or have existed, truly wild in their
present state, but that all are cultivated varieties of species now growing
in great abundance in S. Europe or W. Asia." On the other hand, Alph. De
Candolle (9/20. 'Geograph. Bot.' page 928. The whole subject is discussed
with admirable fulness and knowledge.) has adduced abundant evidence that
common wheat (Triticum vulgare) has been found wild in various parts of
Asia, where it is not likely to have escaped from cultivation: and there is
some force in M. Godron's remark, that, supposing these plants to be
escaped seedlings (9/21. Godron 'De l'Espece' tome 2 page 72. A few years
ago the excellent, though misinterpreted, observations of M. Fabre led many
persons to believe that wheat was a modified descendant of Aegilops; but M.
Godron (tome 1 page 165) has shown by careful experiments that the first
step in the series, viz. Aegilops triticoides, is a hybrid between wheat
and Ae. ovata. The frequency with which these hybrids spontaneously arise,
and the gradual manner in which the Ae. triticoides becomes converted into
true wheat, alone leave any doubt with respect to M. Godron's
conclusions.), as they have propagated themselves in a wild state for
several generations, their continued resemblance to cultivated wheat
renders it probable that the latter has retained its aboriginal character.
But the strong tendency to inheritance, which most of the varieties of
wheat evince, as we shall presently see, is here greatly undervalued. Much
weight must also be attributed to a remark by Professor Hildebrand (9/22.
'Die Verbreitungsmittel der Pflanzen' 1873 page 129.) that when the seeds
or fruit of cultivated plants possess qualities disadvantageous to them as
a means of distribution, we may feel almost sure that they no longer retain
their aboriginal condition. On the other hand, M. De Candolle insists
strongly on the frequent occurrence in the Austrian dominions of rye and of
one kind of oats in an apparently wild condition. With the exception of
these two cases, which however are rather doubtful, and with the exception
of two forms of wheat and one of barley, which he believes to have been
found truly wild, M. De Candolle does not seem fully satisfied with the
other reported discoveries of the parent-forms of our other cereals. With
respect to oats, according to Mr. Buckmann (9/23. Report to British
Association for 1857 page 207.), the wild English Avena fatua can be
converted by a few years of careful cultivation and selection into forms
almost identical with two very distinct cultivated races. The whole subject
of the origin and specific distinctness of the various cereal plants is a
most difficult one; but we shall perhaps be able to judge a little better
after considering the amount of variation which wheat has undergone.
Metzger describes seven species of wheat, Godron refers to five, and De
Candolle to only four. It is not improbable that, besides the kinds known
in Europe, other strongly characterised forms exist in the more distant
parts of the world; for Loiseleur-Deslongchamps (9/24. Considerations sur
les Cereales' 1842-43 page 29.) speaks of three new species or varieties,
sent to Europe in 1822 from Chinese Mongolia, which he considers as being
there indigenous. Moorcroft (9/25. 'Travels in the Himalayan Provinces'
etc. 1841 volume 1 page 224.) also speaks of Hasora wheat in Ladakh as very
peculiar. If those botanists are right who believe that at least seven
species of wheat originally existed, then the amount of variation in any
important character which wheat has undergone under cultivation has been
slight; but if only four or a lesser number of species originally existed,
then it is evident that varieties have arisen so strongly marked, that they
have been considered by capable judges as specifically distinct. But the
impossibility of deciding which forms ought to be ranked as species and
which as varieties, makes it useless to specify in detail the differences
between the various kinds of wheat. Speaking generally, the organs of
vegetation differ little (9/26. Col. J. Le Couteur on the 'Varieties of
Wheat' pages 23, 79.); but some kinds grow close and upright, whilst others
spread and trail along the ground. The straw differs in being more or less
hollow, and in quality. The ears (9/27. Loiseleur-Deslongchamps 'Consid.
sur les Cereales' page 11.) differ in colour and in shape, being
quadrangular, compressed, or nearly cylindrical; and the florets differ in
their approximation to each other, in their pubescence, and in being more
or less elongated. The presence or absence of barbs is a conspicuous
difference, and in certain Gramineae serves even as a generic character
(9/28. See an excellent review in Hooker 'Journ. of Botany' volume 8 page
82 note.); although, as remarked by Godron (9/29. 'De l'Espece' tome 2 page
73.) the presence of barbs is variable in certain wild grasses, and
especially in those such as Bromus secalinus and Lolium temulentum, which
habitually grow mingled with our cereal crops, and which have thus
unintentionally been exposed to culture. The grains differ in size, weight,
and colour; in being more or less downy at one end, in being smooth or
wrinkled, in being either nearly globular, oval, or elongated; and finally
in internal texture, being tender or hard, or even almost horny, and in the
proportion of gluten which they contain.
Nearly all the races or species of wheat vary, as Godron (9/30. Ibid tome 2
page 75.) has remarked, in an exactly parallel manner,--in the seed being
downy or glabrous, and in colour,--and in the florets being barbed or not
barbed, etc. Those who believe that all the kinds are descended from a
single wild species may account for this parallel variation by the
inheritance of a similar constitution, and a consequent tendency to vary in
the same manner; and those who believe in the general theory of descent
with modification may extend this view to the several species of wheat, if
such ever existed in a state of nature.
Although few of the varieties of wheat present any conspicuous difference,
their number is great. Dalbret cultivated during thirty years from 150 to
160 kinds, and excepting in the quality of the grain they all kept true;
Colonel Le Couteur possessed upwards of 150, and Philippar 322 varieties.
(9/31. For Dalbret and Philippar see Loiseleur-Deslongchamps 'Consid. sur
les Cereales' pages 45, 70. Le Couteur on Wheat pages 6, 14-17.) As wheat
is an annual, we thus see how strictly many trifling differences in
character are inherited through many generations. Colonel Le Couteur
insists strongly on this same fact. In his persevering and successful
attempts to raise new varieties, he found that there was only one "secure
mode to ensure the growth of pure sorts, namely, to grow them from single
grains or from single ears, and to follow up the plan by afterwards sowing
only the produce of the most productive so as to form a stock." But Major
Hallett (9/32. See his Essay on 'Pedigree in Wheat' 1862; also paper read
before the British Association 1869 and other publications.) has gone much
farther, and by the continued selection of plants from the grains of the
same ear, during successive generations, has made his 'Pedigree in Wheat'
(and other cereals) now famous in many quarters of the world. The great
amount of variability in the plants of the same variety is another
interesting point, which would never have been detected except by an eye
long practised to the work; thus Colonel Le Couteur relates (9/33.
'Varieties of Wheat' Introduction page 6. Marshall in his 'Rural Economy of
Yorkshire' volume 2 page 9 remarks that "in every field of corn there is as
much variety as in a herd of cattle.") that in a field of his own wheat,
which he considered at least as pure as that of any of his neighbours,
Professor La Gasca found twenty-three sorts; and Professor Henslow has
observed similar facts. Besides such individual variations, forms
sufficiently well marked to be valued and to become widely cultivated
sometimes suddenly appear: thus Mr. Shirreff has had the good fortune to
raise in his lifetime seven new varieties, which are now extensively grown
in many parts of Britain. (9/34. 'Gardener's Chronicle' and 'Agricult.
Gazette' 1862 page 963.)
As in the case of many other plants, some varieties, both old and new, are
far more constant in character than others. Colonel Le Couteur was forced
to reject some of his new sub-varieties, which he suspected had been
produced from a cross, as incorrigibly sportive. On the other hand Major
Hallett (9/35. 'Gardener's Chronicle' November 1868 page 1199.) has shown
how wonderfully constant some varieties are, although not ancient ones, and
although cultivated in various countries. With respect to the tendency to
vary, Metzger (9/36. 'Getreidearten' 1841 s. 66, 91, 92, 116, 117.) gives
from his own experience some interesting facts: he describes three Spanish
sub-varieties, more especially one known to be constant in Spain, which in
Germany assumed their proper character only during hot summers; another
variety kept true only in good land, but after having been cultivated for
twenty-five years became more constant. He mentions two other sub-varieties
which were at first inconstant, but subsequently became, apparently without
any selection, accustomed to their new homes, and retained their proper
character. These facts show what small changes in the conditions of life
cause variability, and they further show that a variety may become
habituated to new conditions. One is at first inclined to conclude with
Loiseleur-Deslongchamps, that wheat cultivated in the same country is
exposed to remarkably uniform conditions; but manures differ, seed is taken
from one soil to another, and, what is far more important, the plants are
exposed as little as possible to struggle with other plants, and are thus
enabled to exist under diversified conditions. In a state of nature each
plant is confined to that particular station and kind of nutriment which it
can seize from the other plants by which it is surrounded.
Wheat quickly assumes new habits of life. The summer and winter kinds were
classed by Linnaeus as distinct species; but M. Monnier (9/37. Quoted by
Godron 'De l'Espece' volume 2 page 74. So it is, according to Metzger
'Getreidearten' s. 18, with summer and winter barley.) has proved that the
difference between them is only temporary. He sowed winter-wheat in spring,
and out of one hundred plants four alone produced ripe seeds; these were
sown and resown, and in three years plants were reared which ripened all
their seed. Conversely, nearly all the plants raised from summer-wheat,
which was sown in autumn, perished from frost; but a few were saved and
produced seed, and in three years this summer-variety was converted into a
winter-variety. Hence it is not surprising that wheat soon becomes to a
certain extent acclimatised, and that seed brought from distant countries
and sown in Europe vegetates at first, or even for a considerable period
(9/38. Loiseleur-Deslongchamps 'Cereales' part 2 page 224. Le Couteur page
70. Many other accounts could be added.) differently from our European
varieties. In Canada the first settlers, according to Kalm (9/39. 'Travels
in North America' 1753-1761 English translation volume 3 page 165.), found
their winters too severe for winter-wheat brought from France, and their
summers often too short for summer-wheat; and they thought that their
country was useless for corn crops until they procured summer-wheat from
the northern parts of Europe, which succeeded well. It is notorious that
the proportion of gluten differs much under different climates. The weight
of the grain is also quickly affected by climate: Loiseleur-Deslongchamps
(9/40. 'Cereales' part 2 pages 179-183.) sowed near Paris 54 varieties,
obtained from the South of France and from the Black Sea, and 52 of these
yielded seed from 10 to 40 per cent heavier than the parent-seed. He then
sent these heavier grains back to the South of France, but there they
immediately yielded lighter seed.
All those who have closely attended to the subject insist on the close
adaptation of numerous varieties of wheat to various soils and climates
even within the same country; thus Colonel Le Couteur (9/41. 'On the
Varieties of Wheat' Introduction page 7. See Marshall 'Rural Econ. of
Yorkshire' volume 2 page 9. With respect to similar cases of adaptation in
the varieties of oats see some interesting papers in the 'Gardener's
Chronicle and Agricult. Gazette' 1850 pages 204, 219.) says, "It is the
suitableness of each sort to each soil that will enable the farmer to pay
his rent by sowing one variety, where he would be unable to do so by
attempting to grow another of a seemingly better sort." This may be in part
due to each kind becoming habituated to its conditions of life, as Metzger
has shown certainly occurs, but it is probably in main part due to innate
differences between the several varieties.
Much has been written on the deterioration of wheat; that the quality of
the flour, size of grain, time of flowering, and hardness, may be modified
by climate and soil, seems nearly certain; but that the whole body of any
one sub-variety ever becomes changed into another and distinct sub-variety,
there is no reason to believe. What apparently does take place, according
to Le Couteur (9/42. 'On the Varieties of Wheat' page 59. Mr. Shirreff and
a higher authority cannot be given ('Gardener's Chronicle and Agricult.
Gazette' 1862 page 963), says "I have never seen grain which has either
been improved or degenerated by cultivation, so as to convey the change to
the succeeding crop.), is, that some one sub-variety out of the many which
may always be detected in the same field is more prolific than the others,
and gradually supplants the variety which was first sown.
With respect to the natural crossing of distinct varieties the evidence is
conflicting, but preponderates against its frequent occurrence. Many
authors maintain that impregnation takes place in the closed flower, but I
am sure from my own observation that this is not the case, at least with
those varieties to which I have attended. But as I shall have to discuss
this subject in another work, it may be here passed over.]
In conclusion, all authors admit that numerous varieties of wheat have
arisen; but their differences are unimportant, unless, indeed, some of the
so-called species are ranked as varieties. Those who believe that from four
to seven wild species of Triticum originally existed in nearly the same
condition as at present, rest their belief chiefly on the great antiquity
of the several forms. (9/43. Alph. De Candolle 'Geograph. Bot.' page 930. )
It is an important fact, which we have recently learnt from the admirable
researches of Heer (9/44. 'Pflanzen der Pfahlbauten' 1866.), that the
inhabitants of Switzerland, even so early as the Neolithic period,
cultivated no less than ten cereal plants, namely, five kinds of wheat, of
which at least four are commonly looked at as distinct species, three kinds
of barley, a panicum, and a setaria. If it could be shown that at the
earliest dawn of agriculture five kinds of wheat and three of barley had
been cultivated, we should of course be compelled to look at these forms as
distinct species. But, as Heer has remarked, agriculture even at the
Neolithic period, had already made considerable progress; for, besides the
cereals, peas, poppies, flax, and apparently apples, were cultivated. It
may also be inferred, from one variety of wheat being the so called
Egyptian, and from what is known of the native country of the panicum and
setaria, as well as from the nature of the weeds which then grew mingled
with the crops, that the lake-inhabitants either still kept up commercial
intercourse with some southern people or had originally proceeded as
colonists from the South.
Loiseleur-Deslongchamps (9/45. 'Les Cereales' page 94.) has argued that, if
our cereal plants have been greatly modified by cultivation, the weeds
which habitually grow mingled with them would have been equally modified.
But this argument shows how completely the principle of selection has been
overlooked. That such weeds have not varied, or at least do not vary now in
any extreme degree, is the opinion of Mr. H.C. Watson and Professor Asa
Gray, as they inform me; but who will pretend to say that they do not vary
as much as the individual plants of the same sub-variety of wheat? We have
already seen that pure varieties of wheat, cultivated in the same field,
offer many slight variations, which can be selected and separately
propagated; and that occasionally more strongly pronounced variations
appear, which, as Mr. Shirreff has proved, are well worthy of extensive
cultivation. Not until equal attention be paid to the variability and
selection of weeds, can the argument from their constancy under
unintentional culture be of any value. In accordance with the principles of
selection we can understand how it is that in the several cultivated
varieties of wheat the organs of vegetation differ so little; for if a
plant with peculiar leaves appeared, it would be neglected unless the
grains of corn were at the same time superior in quality or size. the
selection of seed-corn was strongly recommended (9/46. Quoted by Le Couteur
page 16.) in ancient times by Columella and Celsus; and as Virgil says,--
I've seen the largest seeds, tho' view'd with care,
Degenerate, unless th' industrious hand
Did yearly cull the largest."
But whether in ancient times selection was methodically pursued we may well
doubt, when we hear how laborious the work has been found by Le Coutour and
Hallett. Although the principle of selection is so important, yet the
little which man has effected, by incessant efforts (9/47. A. De Candolle
'Geograph. Bot.' page 932.) during thousands of years, in rendering the
plants more productive or the grains more nutritious than they were in the
time of the old Egyptians, would seem to speak strongly against its
efficacy. But we must not forget that at each successive period the state
of agriculture and the quantity of manure supplied to the land will have
determined the maximum degree of productiveness; for it would be impossible
to cultivate a highly productive variety, unless the land contained a
sufficient supply of the necessary chemical elements.
We now know that man was sufficiently civilised to cultivate the ground at
an immensely remote period; so that wheat might have been improved long ago
up to that standard of excellence which was possible under the then
existing state of agriculture. One small class of facts supports this view
of the slow and gradual improvement of our cereals. In the most ancient
lake-habitations of Switzerland, when men employed only flint-tools, the
most extensively cultivated wheat was a peculiar kind, with remarkably
small ears and grains. (9/48. O. Heer 'Die Pflanzen der Pfahlbauten' 1866.
The following passage is quoted from Dr. Christ in 'Die Fauna der
Pfahlbauten, von Dr. Rutimeyer' 1861 s. 225.) "Whilst the grains of the
modern forms are in section from seven to eight millimetres in length, the
larger grains from the lake-habitations are six, seldom seven, and the
smaller ones only four. The ear is thus much narrower, and the spikelets
stand out more horizontally, than in our present forms." So again with
barley, the most ancient and most extensively cultivated kind had small
ears, and the grains were "smaller, shorter, and nearer to each other, than
in that now grown; without the husk they were 2 1/2 lines long, and
scarcely 1 1/2 broad, whilst those now grown have a length of three lines,
and almost the same in breadth." (9/49. Heer as quoted by Carl Vogt
'Lectures on Man' English translation page 355.) These small-grained
varieties of wheat and barley are believed by Heer to be the parent-forms
of certain existing allied varieties, which have supplanted their early
progenitors.
Heer gives an interesting account of the first appearance and final
disappearance of the several plants which were cultivated in greater or
less abundance in Switzerland during former successive periods, and which
generally differed more or less from our existing varieties. The peculiar
small-eared and small-grained wheat, already alluded to, was the commonest
kind during the Stone period; it lasted down to the Helvetico-Roman age,
and then became extinct. A second kind was rare at first, but afterwards
became more frequent. A third, the Egyptian wheat (T. turgidum), does not
agree exactly with any existing variety, and was rare during the Stone
period. A fourth kind (T. dicoccum) differs from all known varieties of
this form. A fifth kind (T. monococcum) is known to have existed during the
Stone period only by the presence of a single ear. A sixth kind, the common
T. spelta, was not introduced into Switzerland until the Bronze age. Of
barley, besides the short-eared and small-grained kind, two others were
cultivated, one of which was very scarce, and resembled our present common
H. distichum. During the Bronze age rye and oats were introduced; the oat-
grains being somewhat smaller than those produced by our existing
varieties. The poppy was largely cultivated during the Stone period,
probably for its oil; but the variety which then existed is not now known.
A peculiar pea with small seeds lasted from the Stone to the Bronze age,
and then became extinct; whilst a peculiar bean, likewise having small
seeds, came in at the Bronze period and lasted to the time of the Romans.
These details sound like the descriptions given by palaeontologists of the
first appearance, the increasing rarity, and final extinction or
modification of fossil species, embedded in the successive stages of a
geological formation.
Finally, every one must judge for himself whether it is more probable that
the several forms of wheat, barley, rye, and oats are descended from
between ten and fifteen species, most of which are now either unknown or
extinct, or whether they are descended from between four and eight species,
which may have either closely resembled our present cultivated forms, or
have been so widely different as to escape identification. In this latter
case we must conclude that man cultivated the cereals at an enormously
remote period, and that he formerly practised some degree of selection,
which in itself is not improbable. We may, perhaps, further believe that,
when wheat was first cultivated the ears and grains increased quickly in
size, in the same manner as the roots of the wild carrot and parsnip are
known to increase quickly in bulk under cultivation.
[MAIZE OR INDIAN CORN: Zea mays.
Botanists are nearly unanimous that all the cultivated kinds belong to the
same species. It is undoubtedly (9/50. See Alph. De Candolle's long
discussion in his 'Geograph. Bot.' page 942. With respect to New England
see Silliman's 'American Journal' volume 44 page 99.) of American origin,
and was grown by the aborigines throughout the continent from New England
to Chili. Its cultivation must have been extremely ancient, for Tschudi
(9/51. 'Travels in Peru' English translation page 177.) describes two
kinds, now extinct or not known in Peru, which were taken from tombs
apparently prior to the dynasty of the Incas. 'But there is even stronger
evidence of antiquity, for I found on the coast of Peru (9/52. 'Geolog.
Observ. on S. America' 1846 page 49.) heads of maize, together with
eighteen species of recent sea-shell, embedded in a beach which had been
upraised at least 85 feet above the level of the sea. In accordance with
this ancient cultivation, numerous American varieties have arisen. The
aboriginal form has not as yet been discovered in the wild state. A
peculiar kind (9/53. This maize is figured in Bonafous' magnificent work,
'Hist. Nat. du Mais' 1836 P1. v. bis, and in the 'Journal of Hort. Soc.'
volume 1 1846 page 115 where an account is given of the result of sowing
the seed. A young Guarany Indian, on seeing this kind of maize, told
Auguste St. Hilaire (see De Candolle 'Geograph. Bot.' page 951) that it
grew wild in the humid forests of his native land. Mr. Teschemacher in
'Proc. Boston Soc. Hist.' October 19, 1842 gives an account of sowing the
seed.), in which the grains, instead of being naked, are concealed by husks
as much as eleven lines in length, has been stated, but on insufficient
evidence, to grow wild in Brazil. It is almost certain that the aboriginal
form would have had its grains thus protected (9/54. Moquin-Tandon
'Elements de Teratologie' 1841 page 126.); but the seeds of the Brazilian
variety produce, as I hear from Professor Asa Gray, and as is stated in two
published accounts, either common or husked maize; and it is not credible
that a wild species, when first cultivated, should vary so quickly and in
so great a degree.
Maize has varied in an extraordinary and conspicuous manner. Metzger (9/55.
'Die Getreidearten' 1841 s. 208. I have modified a few of Metzger's
statements in accordance with those made by Bonafous in his great work
'Hist. Nat. du Mais' 1836.), who paid particular attention to the
cultivation of this plant, makes twelve races (unter-art) with numerous
sub-varieties: of the latter some are tolerably constant, others quite
inconstant. The different races vary in height from 15-18 feet to only 16-
18 inches, as in a dwarf variety described by Bonafous. The whole ear is
variable in shape, being long and narrow, or short and thick, or branched.
The ear in one variety is more than four times as long as in a dwarf kind.
The seeds are arranged in the ear in from six to even twenty rows, or are
placed irregularly. The seeds are coloured--white, pale-yellow, orange,
red, violet, or elegantly streaked with black (9/56. Godron 'De l'Espece'
tome 2 page 80; Al. De Candolle ibid page 951.); and in the same ear there
are sometimes seeds of two colours. In a small collection I found that a
single grain of one variety nearly equalled in weight seven grains of
another variety. The shape of the seed varies greatly, being very flat, or
nearly globular, or oval; broader than long, or longer than broad; without
any point, or produced into a sharp tooth, and this tooth is sometimes
recurved. One variety (the rugosa of Bonafous, and which is extensively
cultivated in the United States as sweet corn) has its seeds curiously
wrinkled, giving to the whole ear a singular appearance. Another variety
(the cymosa of Bon.) carries its ears so crowded together that it is called
mais a bouquet. The seeds of some varieties contain much glucose instead of
starch. Male flowers sometimes appear amongst the female flowers, and Mr.
J. Scott has lately observed the rarer case of female flowers on a true
male panicle, and likewise hermaphrodite flowers. (9/57. 'Transact. Bot.
Soc. of Edinburgh' volume 8 page 60.) Azara describes (9/58. 'Voyages dans
l'Amerique Meridionale' tome 1 page 147.) a variety in Paraguay the grains
of which are very tender, and he states that several varieties are fitted
for being cooked in various ways. The varieties also differ greatly in
precocity, and have different powers of resisting dryness and the action of
violent wind. (9/59. Bonafous 'Hist. Nat. du Mais' page 31.) Some of the
foregoing differences would certainly be considered of specific value with
plants in a state of nature.
Le Comte Re states that the grains of all the varieties which he cultivated
ultimately assumed a yellow colour. But Bonafous (9/60. Ibid page 31.)
found that most of those which he sowed for ten consecutive years kept true
to their proper tints; and he adds that in the valleys of the Pyrenees and
on the plains of Piedmont a white maize has been cultivated for more than a
century, and has undergone no change.
The tall kinds grown in southern latitudes, and therefore exposed to great
heat, require from six to seven months to ripen their seed; whereas the
dwarf kinds, grown in northern and colder climates, require only from three
to four months. (9/61. Metzger 'Getreidearten' s. 206.) Peter Kalm (9/62.
'Description of Maize' by P. Kalm 1752 in 'Swedish Acts' volume 4. I have
consulted an old English MS. translation.), who particularly attended to
this plant, says, that in the United States, in proceeding from south to
north, the plants steadily diminish in bulk. Seeds brought from lat. 37 deg
in Virginia, and sown in lat. 43-44 deg in New England, produce plants
which will not ripen their seed, or ripen them with the utmost difficulty.
So it is with seed carried from New England to lat. 45-47 deg in Canada. By
taking great care at first, the southern kinds after some years' culture
ripen their seed perfectly in their northern homes, so that this is an
analogous case with that of the conversion of summer into winter wheat, and
conversely. When tall and dwarf maize are planted together, the dwarf kinds
are in full flower before the others have produced a single flower; and in
Pennsylvania they ripen their seeds six weeks earlier than the tall maize.
Metzger also mentions a European maize which ripens its seed four weeks
earlier than another European kind. With these facts, so plainly showing
inherited acclimatisation, we may readily believe Kalm, who states that in
North America maize and some other plants have gradually been cultivated
further and further northward. All writers agree that to keep the varieties
of maize pure they must be planted separately so that they shall not cross.
The effects of the climate of Europe on the American varieties is highly
remarkable. Metzger obtained seed from various parts of America, and
cultivated several kinds in Germany. I will give an abstract of the changes
observed (9/63. 'Getreidearten' s. 208.) in one case, namely, with a tall
kind (Breit-korniger mais, Zea altissima) brought from the warmer parts of
America. During the first year the plants were twelve feet high, and a few
seeds were perfected; the lower seeds in the ear kept true to their proper
form, but the upper seeds became slightly changed. In the second generation
the plants were from nine to ten feet in height, and ripened their seed
better; the depression on the outer side of the seed had almost
disappeared, and the original beautiful white colour had become duskier.
Some of the seeds had even become yellow, and in their now rounded form
they approached common European maize. In the third generation nearly all
resemblance to the original and very distinct American parent-form was
lost. In the sixth generation this maize perfectly resembled a European
variety, described as the second sub-variety of the fifth race. When
Metzger published his book, this variety was still cultivated near
Heidelberg, and could be distinguished from the common kind only by a
somewhat more vigorous growth. Analogous results were obtained by the
cultivation of another American race, the "white-tooth corn," in which the
tooth nearly disappeared even in the second generation. A third race, the
"chicken-corn," did not undergo so great a change, but the seeds became
less polished and pellucid. In the above cases the seeds were carried from
a warm to a colder climate. But Fritz Muller informs me that a dwarf
variety with small rounded seeds (papa-gaien-mais), introduced from Germany
into S. Brazil, produces plants as tall, with seeds as flat, as those of
the kind commonly cultivated there.]
These facts afford the most remarkable instance known to me of the direct
and prompt action of climate on a plant. It might have been expected that
the tallness of the stem, the period of vegetation, and the ripening of the
seed, would have been thus affected; but it is a much more surprising fact
that the seeds should have undergone so rapid and great a change. As,
however, flowers, with their product the seed, are formed by the
metamorphosis of the stem and leaves, any modification in these latter
organs would be apt to extend, through correlation, to the organs of
fructification.
[CABBAGE (Brassica oleracea).
Every one knows how greatly the various kinds of cabbage differ in
appearance. In the Island of Jersey, from the effects of particular culture
and of climate a stalk has grown to the height of sixteen feet, and "had
its spring shoots at the top occupied by a magpie's nest:" the woody stems
are not unfrequently from ten to twelve feet in height, and are there used
as rafters (9/64. 'Cabbage Timber' 'Gardener's Chronicle' 1856 page 744,
quoted from Hooker 'Journal of Botany.' A walking-stick made from a
cabbage-stalk is exhibited in the Museum at Kew.) and as walking-sticks. We
are thus reminded that in certain countries plants belonging to the
generally herbaceous order of the Cruciferae are developed into trees.
Every one can appreciate the difference between green or red cabbages with
great single heads; Brussel-sprouts with numerous little heads; broccolis
and cauliflowers with the greater number of their flowers in an aborted
condition, incapable of producing seed, and borne in a dense corymb instead
of an open panicle; savoys with their blistered and wrinkled leaves; and
borecoles and kails, which come nearest to the wild parent-form. There are
also various frizzled and laciniated kinds, some of such beautiful colours
that Vilmorin in his Catalogue of 1851 enumerates ten varieties which are
valued solely for ornament. Some kinds are less commonly known, such as the
Portuguese Couve Tronchuda, with the ribs of its leaves greatly thickened;
and the Kohlrabi or choux-raves, with their stems enlarged into great
turnip-like masses above the ground; and the recently formed new race
(9/65. 'Journal de la Soc. Imp. d'Horticulture' 1855 page 254 quoted from
'Gartenflora' April 1855.) of the choux-raves, already including nine sub-
varieties, in which the enlarged part lies beneath the ground like a
turnip.
Although we see such great differences in the shape, size, colour,
arrangement, and manner of growth of the leaves and stem, and of the
flower-stems in the broccoli and cauliflower, it is remarkable that the
flowers themselves, the seed-pods and seeds, present extremely slight
differences or none at all. (9/66. Godron 'De l'Espece' tome 2 page 52;
Metzger 'Syst. Beschreibung der Kult. Kohlarten' 1833 s. 6.) I compared the
flowers of all the principal kinds; those of the Couve Tronchuda are white
and rather smaller than in common cabbages; those of the Portsmouth
broccoli have narrower sepals, and smaller, less elongated petals; and in
no other cabbage could any difference be detected. With respect to the
seed-pods, in the purple Kohlrabi alone, do they differ, being a little
longer and narrower than usual. I made a collection of the seeds of twenty-
eight different kinds, and most of them were undistinguishable; when there
was any difference it was excessively slight; thus, the seeds of various
broccolis and cauliflowers, when seen in mass, are a little redder; those
of the early green Ulm savoy are rather smaller; and those of the Breda
kail slightly larger than usual, but not larger than the seeds of the wild
cabbage from the coast of Wales. What a contrast in the amount of
difference is presented if, on the one hand, we compare the leaves and
stems of the various kinds of cabbage with their flowers, pods, and seeds,
and on the other hand the corresponding parts in the varieties of maize and
wheat! The explanation is obvious; the seeds alone are valued in our
cereals, and their variations have been selected; whereas the seeds, seed-
pods, and flowers, have been utterly neglected in the cabbage, whilst many
useful variations in their leaves and stems have been noticed and preserved
from an extremely remote period, for cabbages were cultivated by the old
Celts. (9/67. Regnier 'De l'Economie Publique des Celtes' 1818 page 438.)
It would be useless to give a classified description (9/68. See the elder
De Candolle in 'Transact. of Hort. Soc.' volume 5; and Metzger 'Kohlarten'
etc.) of the numerous races, sub-races, and varieties of the cabbage; but
it may be mentioned that Dr. Lindley has lately proposed (9/69. 'Gardener's
Chronicle' 1859 page 992.) a system founded on the state of development of
the terminal and lateral leaf-buds. Thus:
I. All the leaf-buds active and open, as in the wild-cabbage, kail, etc.
II. All the leaf-buds active, but forming heads, as in Brussel-sprouts,
etc.
III. Terminal leaf-bud alone active, forming a head as in common cabbages,
savoys, etc.
IV. Terminal leaf-bud alone active, and open, with most of the flowers
abortive and succulent, as in the cauliflower and broccoli.
V. All the leaf-buds active and open, with most of the flowers abortive and
succulent, as in the sprouting-broccoli. This latter variety is a new one,
and bears the same relation to common broccoli, as Brussel-sprouts do to
common cabbages; it suddenly appeared in a bed of common broccoli, and was
found faithfully to transmit its newly-acquired and remarkable characters.
The principal kinds of cabbage existed at least as early as the sixteenth
century (9/70. Alph. De Candolle 'Geograph. Bot.' pages 842 and 989.), so
that numerous modifications of structure have been inherited for a long
period. This fact is the more remarkable as great care must be taken to
prevent the crossing of the different kinds. To give proof of this: I
raised 233 seedlings from cabbages of different kinds, which had purposely
been planted near each other, and of the seedlings no less than 155 were
plainly deteriorated and mongrelised; nor were the remaining 78 all
perfectly true. It may be doubted whether many permanent varieties have
been formed by intentional or accidental crosses; for such crossed plants
are found to be very inconstant. One kind, however, called "Cottager's
Kail," has lately been produced by crossing common kail and Brussel-
sprouts, recrossed with purple broccoli (9/71. 'Gardener's Chronicle'
February 1858 page 128.), and is said to be true; but plants raised by me
were not nearly so constant in character as any common kind of cabbage.
Although most of the kinds keep true if carefully preserved from crossing,
yet the seed-beds must be yearly examined, and a few seedlings are
generally found false; but even in this case the force of inheritance is
shown, for, as Metzger has remarked (9/72. 'Kohlarten' s. 22.) when
speaking of Brussel-sprouts, the variations generally keep to their "unter
art," or main race. But in order that any kind may be truly propagated
there must be no great change in the conditions of life; thus cabbages will
not form heads in hot countries, and the same thing has been observed with
an English variety grown during an extremely warm and damp autumn near
Paris. (9/73. Godron 'De l'Espece' tome 2 page 52; Metzger 'Kohlarten' s.
22.) Extremely poor soil also affects the characters of certain varieties.
Most authors believe that all the races are descended from the wild cabbage
found on the western shores of Europe; but Alph. De Candolle (9/74.
'Geograph. Bot.' page 840.) forcibly argues, on historical and other
grounds, that it is more probable that two or three closely allied forms,
generally ranked as distinct species, still living in the Mediterranean
region, are the parents, now all commingled together, of the various
cultivated kinds. In the same manner as we have often seen with
domesticated animals, the supposed multiple origin of the cabbage throws no
light on the characteristic differences between the cultivated forms. If
our cabbages are the descendants of three or four distinct species, every
trace of any sterility which may originally have existed between them is
now lost, for none of the varieties can be kept distinct without scrupulous
care to prevent intercrossing.
The other cultivated forms of the genus Brassica are descended, according
to the view adopted by Godron and Metzger (9/75. Godron 'De l'Espece' tome
2 page 54; Metzger 'Kohlarten' s. 10.), from two species, B. napus and
rapa; but according to other botanists from three species; whilst others
again strongly suspect that all these forms, both wild and cultivated,
ought to be ranked as a single species. Brassica napus has given rise to
two large groups, namely, Swedish turnips (believed to be of hybrid origin)
(9/76. 'Gardener's Chronicle and Agricult. Gazette' 1856 page 729. See more
especially ibid 1868 page 275: the writer asserts that he planted a variety
of cabbage (B. oleracea) close to turnips (B. rapa) and raised from the
crossed seedlings true Swedish turnips. These latter plants ought,
therefore, to be classed with cabbages or turnips, and not under B. napus.)
and Colzas, the seeds of which yield oil. Brassica rapa (of Koch) has also
given rise to two races, namely, common turnips and the oil-giving rape.
The evidence is unusually clear that these latter plants, though so
different in external appearance, belong to the same species; for the
turnip has been observed by Koch and Godron to lose its thick roots in
uncultivated soil; and when rape and turnips are sown together they cross
to such a degree that scarcely a single plant comes true. (9/77.
'Gardener's Chronicle and Agricult. Gazette' 1855 page 730.) Metzger by
culture converted the biennial or winter rape into the annual or summer
rape,--varieties which have been thought by some authors to be specifically
distinct. (9/78. Metzger, 'Kohlarten' s. 51.)
In the production of large, fleshy, turnip-like stems, we have a case of
analogous variation in three forms which are generally considered as
distinct species. But scarcely any modification seems so easily acquired as
a succulent enlargement of the stem or root--that is, a store of nutriment
laid up for the plant's own future use. We see this in our radishes, beet,
and in the less generally known "turnip-rooted" celery, and in the
finocchio, or Italian variety of the common fennel. Mr. Buckman has lately
proved by his interesting experiments bow quickly the roots of the wild
parsnip can be enlarged, as Vilmorin formerly proved in the case of the
carrot. (9/79. These experiments by Vilmorin have been quoted by many
writers. An eminent botanist, Prof. Decaisne, has lately expressed doubts
on the subject from his own negative results, but these cannot be valued
equally with positive results. On the other hand, M. Carriere has lately
stated ('Gardener's Chronicle' 1865 page 1154), that he took seed from a
wild carrot, growing far from any cultivated land, and even in the first
generation the roots of his seedlings differed in being spindle-shaped,
longer, softer, and less fibrous than those of the wild plant. From these
seedlings he raised several distinct varieties.)
This latter plant, in its cultivated state, differs in scarcely any
character from the wild English carrot, except in general luxuriance and in
the size and quality of its roots; but ten varieties, differing in the
colour, shape, and quality of the root, are cultivated in England and come
true by seed. (9/80. Loudon's 'Encyclop. of Gardening' page 835.) Hence
with the carrot, as in so many other cases, for instance with the numerous
varieties and sub-varieties of the radish, that part of the plant which is
valued by man, falsely appears alone to have varied. The truth is that
variations in this part alone have been selected; and the seedlings
inheriting a tendency to vary in the same way, analogous modifications have
been again and again selected, until at last a great amount of change has
been effected.
With respect to the radish, M. Carriere, by sowing the seed of the wild
Raphanus raphanistrum in rich soil, and by continued selection during
several generations, raised many varieties, closely like the cultivated
radish (R. sativus) in their roots, as well as the wonderful Chinese
variety, R. caudatus: (see 'Journal d'Agriculture pratique' tome 1 1869
page 159; also a separate essay 'Origine des Plantes Domestiques' 1869.)
Raphanus raphanistrum and sativus have often been ranked as distinct
species, and owing to differences in their fruit even as distinct genera;
but Professor Hoffman ('Bot. Zeitung' 1872 page 482) has now shown that
these differences, remarkable as they are, graduate away, the fruit of R.
caudatus being intermediate. By cultivating R. raphanistrum during several
generations (ibid 1873 page 9), Professor Hoffman also obtained plants
bearing fruits like those of R. sativus.
PEA (Pisum sativum).
Most botanists look at the garden-pea as specifically distinct from the
field-pea (P. arvense). The latter exists in a wild state in Southern
Europe; but the aboriginal parent of the garden-pea has been found by one
collector alone, as he states, in the Crimea. (9/81. Alph. De Candolle
'Geograph. Bot.' 960. Mr. Bentham 'Hort. Journal' volume 9 1855 page 141
believes that garden and field peas belong to the same species, and in this
respect he differs from Dr. Targioni.) Andrew Knight crossed, as I am
informed by the Rev. A. Fitch, the field-pea with a well-known garden
variety, the Prussian pea, and the cross seems to have been perfectly
fertile. Dr. Alefield has recently studied (9/82. 'Botanische Zeitung' 1860
s. 204.) the genus with care, and, after having cultivated about fifty
varieties, concludes that certainly they all belong to the same species. It
is an interesting fact already alluded to, that, according to O. Heer
(9/83. 'Die Pflanzen der Pfahlbauten' 1866 s. 23.) the peas found in the
lake-habitations of Switzerland of the Stone and Bronze ages, belong to an
extinct variety, with exceedingly small seeds, allied to P. arvense or the
field-pea. The varieties of the common garden-pea are numerous, and differ
considerably from one another. For comparison I planted at the same time
forty-one, English and French varieties. They differed greatly in height,--
namely from between 6 and 12 inches to 8 feet (9/84. A variety called the
Rounciva attains this height, as is stated by Mr. Gordon in 'Transact.
Hort. Soc.' 2nd series volume 1 1835 page 374 from which paper I have taken
some facts.),--in manner of growth, and in period of maturity. Some differ
in general aspect even while only two or three inches in height. The stems
of the Prussian pea are much branched. The tall kinds have larger leaves
than the dwarf kinds, but not in strict proportion to their height:--HAIR'S
DWARF MONMOUTH has very large leaves, and the POIS NAIN HATIF, and the
moderately tall BLUE PRUSSIAN, have leaves about two-thirds of the size of
the tallest kind. In the DANECROFT the leaflets are rather small and a
little pointed; in the QUEEN OF DWARFS rather rounded; and in the QUEEN OF
ENGLAND broad and large. In these three peas the slight differences in the
shape of the leaves are accompanied by slight differences in colour, in the
POIS GEANT SANS PARCHEMIN, which bears purple flowers, the leaflets in the
young plant are edged with red; and in all the peas with purple flowers the
stipules are marked with red.
In the different varieties, one, two, or several flowers in a small
cluster, are borne on the same peduncle; and this is a difference which is
considered of specific value in some of the Leguminosae. In all the
varieties the flowers closely resemble each other except in colour and
size. They are generally white, sometimes purple, but the colour is
inconstant even in the same variety. In WARNER'S EMPEROR, which is a tall
kind, the flowers are nearly double the size of the POIS NAIN HATIF; but
HAIR'S DWARF MONMOUTH, which has large leaves, likewise has large flowers.
The calyx in the VICTORIA MARROW is large, and in BISHOP'S LONG POD the
sepals are rather narrow. In no other kind is there any difference in the
flower.
The pods and seeds, which with natural species afford such constant
characters, differ greatly in the cultivated varieties of the pea; and
these are the valuable, and consequently the selected parts. SUGAR PEAS, or
POIS SANS PARCHEMIN, are remarkable from their thin pods, which, whilst
young, are cooked and eaten whole; and in this group, which, according to
Mr. Gordon includes eleven sub-varieties, it is the pod which differs most;
thus LEWIS'S NEGRO-PODDED PEA has a straight, broad, smooth, and dark-
purple pod, with the husk not so thin as in the other kinds; the pod of
another variety is extremely bowed; that of the POIS GEANT is much pointed
at the extremity; and in the variety "A GRANDS COSSES" the peas are seen
through the husk in so conspicuous a manner that the pod, especially when
dry, can hardly at first be recognised as that of a pea.
In the ordinary varieties the pods also differ much in size;--in colour,
that of WOODFORD'S GREEN MARROW being bright-green when dry, instead of
pale brown, and that of the purple-podded pea being expressed by its name;-
-in smoothness, that of DANECROFT being remarkably glossy, whereas that of
the NE PLUS ULTRA is rugged; in being either nearly cylindrical, or broad
and flat;--in being pointed at the end, as in THURSTON'S RELIANCE, or much
truncated, as in the AMERICAN DWARF. In the AUVERGNE PEA the whole end of
the pod is bowed upwards. In the QUEEN OF THE DWARFS and in SCIMITAR PEAS
the pod is almost elliptic in shape. I here give drawings of the four most
distinct pods produced by the plants cultivated by me.
(FIGURE 41. PODS AND PEAS. I. Queen of Dwarfs. II. American Dwarf. III.
Thurston's Reliance. IV. Pois Geant sans parchemin. a. Dan O'Rourke Pea. b.
Queen of Dwarfs Pea. c. Knight's Tall White Marrow. a. Lewis's Negro Pea.)
In the pea itself we have every tint between almost pure white, brown,
yellow, and intense green; in the varieties of the SUGAR PEAS we have these
same tints, together with red passing through fine purple into a dark
chocolate tint. These colours are either uniform or distributed in dots,
striae, or moss-like marks; they depend in some cases on the colour of the
cotyledons seen through the skin, and in other cases on the outer coats of
the pea itself. In the different varieties, the pods contain, according to
Mr. Gordon, from eleven or twelve to only four or five peas. The largest
peas are nearly twice as much in diameter as the smallest; and the latter
are not always borne by the most dwarfed kinds. Peas differ much in shape,
being smooth and spherical, smooth and oblong, nearly oval in the QUEEN OF
THE DWARFS, and nearly cubical and crumpled in many of the larger kinds.
With respect to the value of the differences between the chief varieties,
it cannot be doubted that, if one of the tall SUGAR-PEAS, with purple
flowers, thin-skinned pods of an extraordinary shape, including large,
dark-purple peas, grew wild by the side of the lowly QUEEN OF THE DWARFS,
with white flowers, greyish-green, rounded leaves, scimitar-like pods,
containing oblong, smooth, pale-coloured peas, which became mature at a
different season: or by the side of one of the gigantic sorts, like the
CHAMPION OF ENGLAND, with leaves of great size, pointed pods, and large,
green, crumpled, almost cubical peas,--all three kinds would be ranked as
distinct species.
Andrew Knight (9/85. 'Phil. Tract.' 1799 page 196.) has observed that the
varieties of peas keep very true, because they are not crossed by insects.
As far as the fact of keeping true is concerned, I hear from Mr. Masters of
Canterbury, well known as the originator of several new kinds, that certain
varieties have remained constant for a considerable time,--for instance,
KNIGHT'S BLUE DWARF, which came out about the year 1820. (9/86. 'Gardener's
Magazine' volume 1 1826 page 153.) But the greater number of varieties have
a singularly short existence: thus Loudon remarks (9/87. 'Encyclopaedia of
Gardening' page 823.) that "sorts which were highly approved in 1821, are
now, in 1833, nowhere to be found;" and on comparing the lists of 1833 with
those of 1855, I find that nearly all the varieties have changed. Mr.
Masters informs me that the nature of the soil causes some varieties to
lose their character. As with other plants, certain varieties can be
propagated truly, whilst others show a determined tendency to vary; thus
two peas differing in shape, one round and the other wrinkled, were found
by Mr. Masters within the same pod, but the plants raised from the wrinkled
kind always evinced a strong tendency to produce round peas. Mr. Masters
also raised from a plant of another variety four distinct sub-varieties,
which bore blue and round, white and round, blue and wrinkled, and white
and wrinkled peas; and although he sowed these four varieties separately
during several successive years, each kind always reproduced all four kinds
mixed together!
With respect to the varieties not naturally intercrossing, I have
ascertained that the pea, which in this respect differs from some other
Leguminosae, is perfectly fertile without the aid of insects. Yet I have
seen humble-bees whilst sucking the nectar depress the keel-petals, and
become so thickly dusted with pollen, that it could hardly fail to be left
on the stigma of the next flower which was visited. Nevertheless, distinct
varieties growing closely together rarely cross; and I have reason to
believe that this is due to their stigmas being prematurely fertilised in
this country by pollen from the same flower. The horticulturists who raise
seed-peas are thus enabled to plant distinct varieties close together
without any bad consequences; and it is certain, as I have myself found,
that true seed may be saved during at least several generations under these
circumstances. (9/88. See Dr. Anderson to the same effect in the 'Bath Soc.
Agricultural Papers' volume 4 page 87.) Mr. Fitch raised, as he informs me,
one variety for twenty years, and it always came true, though grown close
to other varieties. From the analogy of kidney-beans I should have expected
(9/89. I have published full details of experiments on this subject in the
'Gardener's Chronicle' 1857 October 25.) that varieties thus circumstanced
would have occasionally crossed; and I shall give in the eleventh chapter
two cases of this having occurred, as shown (in a manner hereafter to be
explained) by the pollen of the one variety having acted directly on the
seeds of the other. Whether many of the new varieties which incessantly
appear are due to such occasional and accidental crosses, I do not know.
Nor do I know whether the short existence of almost all the numerous
varieties is the result of mere change of fashion, or of their having a
weak constitution, from being the product of long-continued self-
fertilisation. It may, however, be noticed that several of Andrew Knight's
varieties, which have endured longer than most kinds, were raised towards
the close of the last century by artificial crosses; some of them, I
believe, were still vigorous in 1860; but now, in 1865, a writer, speaking
(9/90. 'Gardener's Chronicle' 1865 page 387.) of Knight's four kinds of
marrows, says, they have acquired a famous history, but their glory has
departed.
With respect to Beans (Faba vulgaris), I will say but little. Dr. Alefield
has given (9/91. 'Bonplandia' 10, 1862 s. 348.) short diagnostic characters
of forty varieties. Everyone who has seen a collection must have been
struck with the great difference in shape, thickness, proportional length
and breadth, colour, and size which beans present. What a contrast between
a Windsor and Horse-bean! As in the case of the pea, our existing varieties
were preceded during the Bronze age in Switzerland (9/92. Heer 'Die
Pflanzen der Pfahlbauten' 1866 s. 22.) by a peculiar and now extinct
variety producing very small beans. (9/93. Mr. Bentham informs me that in
Poitou and the adjoining parts of France, varieties of Phaseolus vulgaris
are extremely numerous, and so different that they were described by Savi
as distinct species. Mr. Bentham believes that all are descended from an
unknown eastern species. Although the varieties differ so greatly in
stature and in their seeds, "there is a remarkable sameness in the
neglected characters of foliage and flowers, and especially in the
bracteoles, an insignificant character in the eyes even of botanists.")
POTATO (Solanum tuberosum).
There is little doubt about the parentage of this plant; for the cultivated
varieties differ extremely little in general appearance from the wild
species, which can be recognised in its native land at the first glance.
(9/94. Darwin 'Journal of Researches' 1845 page 285. Sabine in 'Transact.
Hort. Soc.' volume 5 page 249.) The varieties cultivated in Britain are
numerous; thus Lawson (9/95. 'Synopsis of the Vegetable Products of
Scotland' quoted in Wilson's 'British Farming' page 317.) gives a
description of 175 kinds. I planted eighteen kinds in adjoining rows; their
stems and leaves differed but little, and in several cases there was as
great a difference between the individuals of the same variety as between
the different varieties. The flower varied in size, and in colour between
white and purple, but in no other respect, except that in one kind the
sepals were somewhat elongated. One strange variety has been described
which always produces two sorts of flowers, the first double and sterile,
the second single and fertile. (9/96. Sir G. Mackenzie, in 'Gardener's
Chronicle' 1845 page 790.) The fruit or berries also differ, but only in a
slight degree. (9/97. Putsche und Vertuch 'Versuch einer Monographie der
Kartoffeln' 1819 s. 9, 15. See also Dr. Anderson 'Recreations in
Agriculture' volume 4 page 325.) The varieties are liable in very different
degree to the attack of the Colorado potato-beetle. (9/98. Walsh 'The
American Entomologist' 1869 page 160. Also S. Tenney 'The American
Naturalist' May 1871 page 171.)
The tubers, on the other hand, present a wonderful amount of diversity.
This fact accords with the principle that the valuable and selected parts
of all cultivated productions present the greatest amount of modification.
They differ much in size and shape, being globular, oval, flattened,
kidney-like, or cylindrical. One variety from Peru is described (9/99.
'Gardener's Chronicle' 1862 page 1052.) as being quite straight, and at
least six inches in length, though no thicker than a man's finger. The eyes
or buds differ in form, position, and colour. The manner in which the
tubers are arranged on the so-called roots or rhizomes is different; thus,
in the gurken-kartoffeln they form a pyramid with the apex downwards, and
in another variety they bury themselves deep in the ground. The roots
themselves run either near the surface or deep in the ground. The tubers
also differ in smoothness and colour, being externally white, red, purple,
or almost black, and internally white, yellow, or almost black. They differ
in flavour and quality, being either waxy or mealy; in their period of
maturity, and in their capacity for long preservation.
As with many other plants which have been long propagated by bulbs, tubers,
cuttings, etc., by which means the same individual is exposed during a
length of time to diversified conditions, seedling potatoes generally
display innumerable slight differences. Several varieties, even when
propagated by tubers, are far from constant, as will be seen in the chapter
on Bud-variation. Dr. Anderson (9/100. 'Bath Society Agricult. Papers'
volume 5 page 127. And 'Recreations in Agriculture' volume 5 page 86.)
procured seed from an Irish purple potato, which grew far from any other
kind, so that it could not at least in this generation have been crossed,
yet the many seedlings varied in almost every possible respect, so that
"scarcely two plants were exactly alike." Some of the plants which closely
resembled each other above ground, produced extremely dissimilar tubers;
and some tubers which externally could hardly be distinguished, differed
widely in quality when cooked. Even in this case of extreme variability,
the parent-stock had some influence on the progeny, for the greater number
of the seedlings resembled in some degree the parent Irish potato. Kidney
potatoes must be ranked amongst the most highly cultivated and artificial
races; nevertheless their peculiarities can often be strictly propagated by
seed. A great authority, Mr. Rivers (9/101. 'Gardener's Chronicle' 1863
page 643.) states that "seedlings from the ash-leaved kidney always bear a
strong resemblance to their parent. Seedlings from the fluke-kidney are
still more remarkable for their adherence to their parent stock, for, on
closely observing a great number during two seasons, I have not been able
to observe the least difference, either in earliness, productiveness, or in
the size or shape of their tubers."