CHAPTER IX. 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[1] 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[2] 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[3] 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[4] 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,[5] 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[6] 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.[7]

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.[8]

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]

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[10] 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.[11] 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[12] 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.”[13] 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[1] 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[15] 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[16] 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.’[17]

_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[18] 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,[19] “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[20] 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,[21] 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[22] 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,[23] 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[24] speaks of

three new species or varieties, sent to Europe in 1822 from Chinese

Mongolia, which he considers as being there indigenous. Moorcroft[25]

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;[26] 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[27]

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 Gramineæ serves even as a generic character;[28] although, as

remarked by Godron,[29] 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[30] 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.[31] 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[32] 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[33] 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.[34]

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[35] 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[36] 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 Linnæus as distinct species; but M. Monnier[37] 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,[38]

differently from our European varieties. In Canada the first settlers,

according to Kalm,[39] 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[40] 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[41] 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,[42] 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.[43] It is an important fact,

which we have recently learnt from the admirable researches of

Heer,[44] 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[45] 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[46] 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[47] 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.[48] “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 2½

lines long, and scarcely 1½ broad, whilst those now grown have a length

of three lines, and almost the same in breadth.”[49] 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

palæontologists 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[50] 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[51] 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[52]

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,[53] 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;[54] 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,[55] 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;[56] 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 _maïs à 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.[57] Azara describes[58] 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.[59] Some of the

foregoing differences would certainly be considered of specific value

with plants in a state of nature.

Le Comte Ré states that the grains of all the varieties which he

cultivated ultimately assumed a yellow colour. But Bonafous[60] 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.[61] Peter Kalm,[62] 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° in Virginia, and sown in lat. 43°-44° 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° 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[63] 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 Müller 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[64] and as

walking-sticks. We are thus reminded that in certain countries plants

belonging to the generally herbaceous order of the Cruciferæ 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[65] 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.[66] 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.[67]

It would be useless to give a classified description[68] of the

numerous races, sub-races, and varieties of the cabbage; but it may be

mentioned that Dr. Lindley has lately proposed[69] 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,[70] 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,[71] 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[72] 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.[73] 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[74] 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,[75] 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)[76] 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.[77]

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.[78]

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.[79]

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.[80] 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. Carrière, 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,’ tom. i,

1869, p. 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, p. 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, p. 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.[81] 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[82] 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,[83] 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,[84]—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 géant 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 Leguminosæ. 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 _P_, 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

géant_ is much pointed at the extremity; and in the variety “à 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.

Illustration: Fig. 41.—Pods of the Common 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, striæ, 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[85] 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.[86] But the greater

number of varieties have a singularly short existence: thus Loudon

remarks[87] 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

Leguminosæ, 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.[88] 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[89] 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[90] 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[91] 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[92] by a peculiar and now

extinct variety producing very small beans.[93]

_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.[94] The varieties cultivated in

Britain are numerous; thus Lawson[95] 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.[96] The fruit or berries also

differ, but only in a slight degree.[97] The varieties are liable in

very different degree to the attack of the Colorado potato-beetle.[98]

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[99] 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[100] 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,[101] 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.”

REFERENCES

[1] ‘Géographie botanique raisonnée,’ 1855, pp. 810 to 991.

[2] Review by Mr. Bentham in ‘Hort. Journal,’ vol. ix 1855, p. 133,

entitled, ‘Historical Notes on cultivated Plants,’ by Dr. A.

Targioni-Tozzetti. _See also_ ‘Edinburgh Review,’ 1866, p. 510.

[3] ‘Hist. Notes,’ as above by Targioni-Tozzetti.

[4] ‘Considérations sur les Céréales,’ 1842, p. 37. ‘Géographie Bot.,’

1855, p. 930. “Plus on suppose l’agriculture ancienne et remontant à

une époque d’ignorance, plus il est probable que les cultivateurs

avaient choisi des especes offrant à l’origine meme un avantage

incontestable.”

[5] Dr. Hooker has given me this information. _See also_ his

‘Himalayan Journals,’ 1854, vol. ii. p. 49.

[6] ‘Travels in Central Africa,’ Eng. translat. vol. i. pp. 529 and

390; vol. ii. pp. 29, 265, 270. Livingstone’s ‘Travels,’ p. 551.

[7] For instance in both North and South America. Mr. Edgeworth

(‘Journal Proc. Linn. Soc.,’ vol. vi. Bot., 1862, p. 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.

[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.

[9] ‘Travels,’ p. 535. Du Chaillu, ‘Adventures in Equatorial Africa,’

1861, p. 445.

[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.

[11] ‘American Acad. of Arts and Sciences,’ April 10th, 1860, p. 413.

Downing, ‘The Fruits of America,’ 1845, p. 261.

[12] ‘Journals of Expeditions in Australia,’ 1841, vol. ii. p. 292.

[13] Darwin’s ‘Journal of Researches,’ 1845, p. 215.

[14] De Candolle has tabulated the facts in the most interesting

manner in his ‘Géographie Bot.,’ p. 986.

[15] ‘Flora of Australia,’ Introduction, p. 110.

[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,’ vol. xxiv.

Nov. 1857, p. 441. For the traditions of the natives of New Zealand

_see_ Crawfurd’s ‘Grammar and Dict. of the Malay Language,’ 1852, p.

260.

[17] _See,_ for example, Mr. Hewett C. Watson’s remarks on our wild

plums and cherries and crabs: ‘Cybele Britannica,’ vol. i. pp. 330,

334, etc. Van Mons (in his ‘Arbres Fruitiers,’ 1835, tom. i. p. 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.

[18] _See_ A. De Candolle, ‘Géograph. Bot.,’ 1855, p. 928 _et seq._

Godron, ‘De l’Espèce,’ 1859, tom. ii. p. 70; and Metzger, ‘Die

Getreidearten,’ etc., 1841.

[19] Mr. Bentham, in his review, entitled ‘Hist. Notes on cultivated

Plants,’ by Dr. A. Targioni-Tozzetti, in ‘Journal of Hort. Soc.,’ vol.

ix., 1855, p. 133. He informs me that he still retains the same

opinion.

[20] ‘Géograph. Bot.,’ p. 928. The whole subject is discussed with

admirable fulness and knowledge.

[21] Godron, ‘De l’Espèce,’ tom. ii. p. 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 Ægilops;

but M. Godron (tom. i. p. 165) has shown by careful experiments that

the first step in the series, viz. _ Ægilops triticoides,_ is a hybrid

between wheat and _ Æ. ovata._ The frequency with which these hybrids

spontaneously arise, and the gradual manner in which the _ Æ.

triticoides_ becomes converted into true wheat, alone leave any doubt

with respect to M. Godron’s conclusions.

[22] ‘Die Verbreitungsmittel der Pflanzen,’ 1873, p. 129.

[23] Report to British Association for 1857, p. 207.

[24] ‘Considérations sur les Céréales,’ 1842-43, p. 29.

[25] ‘Travels in the Himalayan Provinces,’ etc., 1841, vol. i. p. 224.

[26] Col. J. Le Couteur on the ‘Varieties of Wheat,’ pp. 23, 79.

[27] Loiseleur-Deslongchamps, ‘Consid. sur les Céréales,’ p. 11.

[28] _See_ an excellent review in Hooker’s ‘Journ. of Botany,’ vol.

viii. p. 82 note.

[29] ‘De l’Espèce,’ tom. ii. p. 73.

[30] Ibid., tom. ii. p. 75.

[31] For Dalbret and Philippar, _see_ Loiseleur-Deslongchamps ‘Consid.

sur les Céréales,’ pp. 45, 70. Le Couteur on Wheat, pp. 6, 14-17.

[32] _See_ his Essay on ‘Pedigree in Wheat,’ 1862; also paper read

before the British Association, 1869, and other publications.

[33] ‘Varieties of Wheat,’ Introduction, p. 6. Marshall, in his ‘Rural

Economy of Yorkshire,’ vol. ii. p. 9, remarks that “in every field of

corn there is as much variety as in a herd of cattle.”

[34] ‘Gardener’s Chron.’ and ‘Agricult. Gazette,’ 1862, p. 963.

[35] ‘Gardener’s Chron.’ Nov. 1868, p. 1199.

[36] ‘Getreidearten,’ 1841, s. 66, 91, 92, 116, 117.

[37] Quoted by Godron, ‘De l’Espèce,’ vol. ii. p. 74. So it is,

according to Metzger (‘Getreidearten,’ s. 18), with summer and winter

barley.

[38] Loiseleur-Deslongchamps, ‘Céréales,’ part ii. p. 224. Le Couteur,

p. 70. Many other accounts could be added.

[39] ‘Travels in North America,’ 1753-1761, Eng. translat., vol. iii

p. 165.

[40] ‘Céréales,’ part ii. pp. 179-183.

[41] ‘On the Varieties of Wheat,’ Introduct., p. 7. _See_ Marshall

‘Rural Econ. of Yorkshire,’ vol. ii. p. 9. With respect to similar

cases of adaptation in the varieties of oats, _ see_ some interesting

papers in the ‘Gardener’s Chron. and Agricult. Gazette,’ 1850, pp.

204, 219.

[42] ‘On the Varieties of Wheat,’ p. 59. Mr. Shirreff, and a higher

authority cannot be given (‘Gard. Chron. and Agricult. Gazette,’ 1862,

p. 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.”

[43] Alph. De Candolle, ‘Géograph. Bot.,’ p. 930.

[44] ‘Pflanzen der Pfahlbauten,’ 1866.

[45] ‘Les Céréales,’ p. 94.

[46] Quoted by Le Couteur, p. 16.

[47] A. De Candolle, ‘Geograph. Bot.,’ p. 932.

[48] O. Heer ‘Die Pflanzen der Pfahlbauten,’ 1866. The following

passage is quoted from Dr. Christ, in ‘Die Fauna der Pfahlbauten, von

Dr. Rütimeyer,’ 1861, s. 225.

[49] Heer, as quoted by Carl Vogt, ‘Lectures on Man,’ Eng. translat.,

p. 355.

[50] _See_ Alph. De Candolle’s long discussion in his ‘Géograph.

Bot.,’ p. 942. With respect to New England, _ see_ Silliman’s

‘American Journal,’ vol. xliv. p. 99.

[51] ‘Travels in Peru,’ Eng. translat., p. 177.

[52] ‘Geolog. Observ. on S. America,’ 1846, p. 49.

[53] This maize is figured in Bonafous’ magnificent work, ‘Hist. Nat.

du Mais,’ 1836, Pl. v. bis, and in the ‘Journal of Hort. Soc.,’ vol.

i. 1846, p. 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, ‘Géograph. Bot.,’ p. 951) that

it grew wild in the humid forests of his native land. Mr.

Teschemacher. in ‘Proc. Boston Soc. Hist.,’ Oct. 19th, 1842, gives an

account of sowing the seed.

[54] Moquin-Tandon, ‘Eléments de Tératologie,’ 1841, p. 126.

[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.

[56] Godron ‘De l’Espèce,’ tom. ii. p. 80; Al. De Candolle, ibid., p.

951.

[57] ‘Transact. Bot. Soc. of Edinburgh,’ vol. viii. p. 60.

[58] ‘Voyages dans l’Amérique Méridionale,’ tom. i. p. 147.

[59] Bonafous’ ‘Hist. Nat. du Maïs,’ p. 31.

[60] Ibid., p. 31.

[61] Metzger, ‘Getreidearten,’ s. 206.

[62] ‘Description of Maize,’ by P. Kalm, 1752, in ‘Swedish Acts,’ vol.

iv. I have consulted an old English MS. translation.

[63] ‘Getreidearten,’ s. 208.

[64] Cabbage Timber, ‘Gardener’s Chron.,’ 1856, p. 744, quoted from

Hooker’s ‘Journal of Botany.’ A walking-stick made from a

cabbage-stalk is exhibited in the Museum at Kew.

[65] ‘Journal de la Soc. Imp. d’Horticulture,’ 1855, p. 254, quoted

from ‘Gartenflora,’ April, 1855.

[66] Godron ‘De l’Espèce,’ tom. ii. p. 52; Metzger, ‘Syst.

Beschreibung der Kult. Kohlarten,’ 1833, s. 6.

[67] Regnier, ‘De l’Economie Publique des Celtes,’ 1818, p. 438.

[68] _See_ the elder De Candolle, in ‘Transact. of Hort. Soc.,’ vol.

v.; and Metzger ‘Kohlarten,’ etc.

[69] ‘Gardener’s Chronicle,’ 1859, p. 992.

[70] Alph. De Candolle, ‘Géograph. Bot.’ pp. 842 and 989.

[71] ‘Gardener’s Chron.,’ Feb. 1858, p. 128.

[72] ‘Kohlarten,’ s. 22.

[73] Godron, ‘De l’Espèce,’ tom. ii. p. 52; Metzger, ‘Kohlarten,’ s.

22.

[74] ‘Géograph. Bot.,’ p. 840.

[75] Godron, ‘De l’Espèce,’ tom. ii. p. 54; Metzger, ‘Kohlarten,’ s.

10.

[76] ‘Gardener’s Chron. and Agricult. Gazette,’ 1856, p. 729. _ See,_

more especially, ibid., 1868, p. 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._

[77] ‘Gardener’s Chron. and Agricult. Gazette,’ 1855, p. 730.

[78] Metzger, ‘Kohlarten,’ s. 51.

[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. Carrière has

lately stated (‘Gard. Chronicle,’ 1865, p. 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.

[80] Loudon’s ‘Encyclop. of Gardening,’ p. 835.

[81] Alph. De Candolle ‘Géograph. Bot.,’ 960. Mr. Bentham (‘Hort.

Journal,’ vol. ix. 1855, p. 141) believes that garden and field peas

belong to the same species, and in this respect he differs from Dr.

Targioni.

[82] ‘Botanische Zeitung,’ 1860, s. 204.

[83] ‘Die Pflanzen der Pfahlbauten,’ 1866, s. 23.

[84] A variety called the Rounciva attains this height, as is stated

by Mr. Gordon in ‘Transact. Hort. Soc.’ (2nd series), vol. i. 1835, p.

374, from which paper I have taken some facts.

[85] ‘Phil. Tract.,’ 1799, p. 196.

[86] ‘Gardener’s Magazine,’ vol. i., 1826, p. 153.

[87] ‘Encyclopædia of Gardening,’ p. 823.

[88] _See_ Dr. Anderson to the same effect in the ‘Bath Soc.

Agricultural Papers,’ vol. iv. p. 87.

[89] I have published full details of experiments on this subject in

the ‘Gardener’s Chronicle,’ 1857, Oct. 25th.

[90] ‘Gardener’s Chronicle,’ 1865, p. 387.

[91] ‘Bonplandia,’ x., 1862, s. 348.

[92] Heer, ‘Die Pflanzen der Pfahlbauten,’ 1866, s. 22.

[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.”

[94] Darwin, ‘Journal of Researches,’ 1845, p. 285. Sabine, in

‘Transact. Hort. Soc.,’ vol. v. p. 249.

[95] ‘Synopsis of the Vegetable Products of Scotland,’ quoted in

Wilson’s ‘British Farming,’ p. 317.

[96] Sir G. Mackenzie, in ‘Gardener’s Chronicle,’ 1845, p. 790.

[97] Putsche und Vertuch ‘Versuch einer Monographie der Kartoffeln,’

1819, s. 9, 15. _See also_ Dr. Anderson ‘Recreations in Agriculture,’

vol. iv. p. 325.

[98] Walsh, ‘The American Entomologist,’ 1869, p. 160. Also S. Tenney,

‘The American Naturalist,’ May 1871, p. 171.

[99] ‘Gardener’s Chronicle,’ 1862, p. 1052.

[100] ‘Bath Society Agricult. Papers,’ vol. v. p. 127. And

‘Recreations in Agriculture,’ vol. v. p. 86.

[101] ‘Gardener’s Chronicle,’ 1863, p. 643.