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Show 322 CEREAL PLANTS. CHAP. lX. three to foUl' months.•s Peter Kalm,09 who particularly attended to this plant, says, that in tho United States, in proceeding from south to.nor~h, tho plants steadily diminish in bulle Seeds brought from lat. 37° m V.n·ginia, and sown in lat. 43::>-44° in Now England, produc~ plants wJuc~1 will not ripon thch· , cod, or ripen them with tho utmost ~Jfficult.y. So 1t is with seed carried from Now England to lat. 45°-4.7° m Camtda. By taki11g great care at first, the southern kinds after some y~ar~' cultmc ripen their so d perfectly in their northern homes, ~o tha~ tlu. JS an ann.logons case with tltat of tho conversion of summer mto wmtcr wheat, a.nd convcr ·ely. When tall and dwarf maize arc planted togoth~r, the dwarf kinds arc in fnll flower before the other.· have produced a smglc flower; and in Pennsylvania they 1·ipcn their so d six wc?ks ca~licr ~hau t!10 tn.ll maize. Metzger also mentions a European 1~a1~r.O wl~1ch npcns 1ts seed four weeks earlier than another European kmd. W1th the. ·c facts, so plainly showing inherited acclimatisation, we may readily believe Kalm, who states that in North America maize and some other plants have gradually boon cultivated further and fmthm: northward. All writers agree tlmt to keep tho varieties of maize pmo they must be planted separately so that they shall not cross. . . . . . Tho effects of tho climate of Europe on tho AmeriCan varwtws IS b1ghly remarkable. Metzger obtained seed from various parts of America, and cultivated several kinds in Germany. I will give an abstract of the chan"'CS observed 60 in one case, namely, with a t .dl kind (Broit-kornigcr mays~ Zca altissima) brought from tho warmer parts of America. During tho first year tho plants wore twelve feat high, and few seeds were perfected; the lower seeds in tbo car kept true to their proper form, but the upper seeds became slightly changed. In tho second generation the plants wore from nino to ten feet in height, and ripened their seed bettor; 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 bad even become yellow, and in their now rounded form they approached common European maize. In tho third generation nearly all resemblance to tho original and very distinct American parent-form was lost. In tho sixth generation this maize perfectly resembled a European variety, described as tho second sub-variety of the fifth race. When Metzger published ills book, this variety war; still cultivated near Heidelberg, and could be distinguished from the common kind only by a somewhat more vigorous growth. Analogous results wore obtained by tho cultivation of another American race, the "white-tooth corn," in which the tooth nearly disappeared even in tho second generation. A third race, tho "chicken-corn," did not undergo so groat a chango, but tho seeds became less polished and pellucid. These facts afford the most remarkable instance known to me of the direct and prompt action of climate on a plant. It might •e Metzger,' Getr idenrten,' s. 206. S9 'Description ofl\faize,' by P. Kalm, 1752, in 'Swedish Acts,' vol. iv. I have consnUcd an old English MS. translation. 60 'Getreideartcn,' s. 208. CliAP. lX. CULINARY PLANTS: CABBAGES. 323 have been expected that the tallness of the stem, the period of vegetation, and the ripening of the seed, would have been thus affected ; unt it is a much more surprising fact that tho seeds should have undergone so rapid anu great a change. As, however, flowers, with their product the seeu, 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. (Yabbage ( flrctssica oleracen ).-Every one knows how greatly tho various kinds of cabbage differ in appearance. In the island of Jersey, from the eftccts of particular culture and of climate, a stalk has grown to tho height of sixteen feet, and "had its spring shoots at the top occupied by a magpic's nest:" tho woody stems arc not unfrequontly from ten to twelve feet in height, and arc there used as rafters 61 and as walking-sticks. W o arc thus reminded that in certain countries plants belonging to the generally herbaceous order of the Cruciform arc developed into trees. Every one can appreciate the diJforence between green or rod cabbages with great single heads; Brussol-sprouts with numerous little heads; l?roccolis and cauliflowers with tho 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 Wl'inklcd leaves; and borecoles and kales, which como nearest to tho wild parent-form. Thoro arc also various frizzled and laciniate<l kinds, some of such beautiful colours that Vilmorin in his Catalogue of 1851 enumerates ten varieties, valued solely for ornament, which arc propagated by seed. Some kinds are less commonly known, such as the Portuguese Couve Tronchuda, with tho ribs of its leaves greatly thickened; and tho Kohlrabi or choux-raves, with their stems enlarged into great turnip-like masses above the g~·ound; and the recently formed new race f>2 of choux-ravos, already including nine sub-varieties, in which the enlarged part lies beneath tho ground like a turnip. Although we see such great differences in tho shape, size, colour, arrangemont, and manner of growth of tho leaves and stem, and of the flowerstems in tho broccoli and cauliflower, it is remarkable that tho flowers themselves, tho seed-pods, and seeds, present extremely slight differences or none at all.63 I compared the flowers of all the principal kinds; those of tbo Oouve Trouchuda are white and rather smaller than in common cabbages; those of tho Portsmouth broccoli have narrower sepals, and smaller, less elongated petals; and in no other cabbage could any difference bo detected. With respect to the seed-pods, in the purple Kohlrabi alone, 6! ' Cabbn.ge 'Timber,' ' Gardener's Chrou.,' 1856, p. 744, quoted from llookcr's ' Journal of Botany.' A walking·stick made from a cabbngcstalk i::; exhibited in the Museum nt Kew. r.2 'Journal tle ]a Soc. Imp. d'Ilorticulture,' 1855, p. 254, quoted from' Gartenfiora,' Ap. 1855. 6a Godron, • De l'Espcce,' tom. ii. p. 52 ; Metzger, ' Syst. Beschreibung der Kul t. Kohlarteu,' 1833, s. 6. y ~ |