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.