Nevertheless, in most of the cases given in the following list, the cotyledons may be as certainly said to sleep as may the leaves of any plant. In two cases, namely with the cabbage and radish, the cotyledons of which rise almost vertically during the few first nights of their life, it was ascertained by placing young seedlings in the klinostat, that the upward movement was not due to apogeotropism.
The names of the plants, the cotyledons of which stand at night at an angle of at least 60o with the horizon, are arranged in the appended list on the same system as previously followed. The numbers of the Families, and with the Leguminosae the numbers of the Tribes, have been added to show how widely the plants in question are distributed throughout the [page 300] dicotyledonous series. A few remarks will have to be made about many of the plants in the list. In doing so, it will be convenient not to follow strictly any systematic order, but to treat of the Oxalidae and the Leguminosae at the close; for in these two Families the cotyledons are generally provided with a pulvinus, and their movements endure for a much longer time than those of the other plants in the list.
List of Seedling Plants, the cotyledons of which rise or sink at night to an angle of at least 60o above or beneath the horizon.
Brassica oleracea. Cruciferae (Fam. 14). -- napus (as we are informed by Prof. Pfeffer). Raphanus sativus. Cruciferae. Githago segetum. Caryophylleae (Fam. 26). Stellaria media (according to Hofmeister, as quoted). Caryophylleae. Anoda Wrightii. Malvaceae (Fam. 36). Gossypium (var. Nankin cotton). Malvaceae. Oxalis rosea. Oxalidae (Fam. 41). -- floribunda. -- articulata. -- Valdiviana. -- sensitiva. Geranium rotundifolium. Geraniaceae (Fam. 47). Trifolium subterraneum. Leguminosae (Fam. 75, Tribe 3). -- strictum. -- leucanthemum. Lotus ornithopopoides. Leguminosae (Tribe 4). -- peregrinus. -- Jacobaeus. Clianthus Dampieri. Leguminosae (Tribe 5)--according to M. Ramey. Smithia sensitiva. Leguminosae (Tribe 6). Haematoxylon Campechianum. Leguminosae (Tribe 13)--according to Mr. R. I. Lynch. Cassia mimosoides. Leguminosae (Tribe 14). -- glauca. -- florida. -- corymbosa. -- pubescens. -- tora. -- neglecta. -- 3 other Brazilian unnamed species. Bauhinia (sp.?. Leguminosae (Tribe 15). Neptunia oleracea. Leguminosae (Tribe 20). Mimosa pudica. Leguminosae (Tribe 21). -- albida. Cucurbita ovifera. Cucurbitaceae (Fam. 106). -- aurantia. Lagenaria vulgaris. Cucurbitaceae. Cucumis dudaim. Cucurbitaceae. Apium petroselinum. Umbelliferae (Fam. 113). -- graveolens. Lactuca scariola. Compositae (Fam. 122). Helianthus annuus (?). Compositae. Ipomoea caerulea. Convolvulaceae (Fam. 151). -- purpurea. -- bona-nox. -- coccinea. [page 301] List of Seedling Plants (continued). Solanum lycopersicum. Solaneae (Fam. 157.) Mimulus, (sp. ?) Scrophularineae (Fam. 159)--from information given us by Prof. Pfeffer. Mirabilis jalapa. Nyctagineae (Fam. 177). Mirabilis longiflora. Beta vulgaris. Polygoneae (Fam. 179). Amaranthus caudatus. Amaranthaceae (Fam. 180). Cannabis sativa (?). Cannabineae (Fam. 195).
Brassica oleracea (Cruciferae).--It was shown in the first chapter that the cotyledons of the common cabbage rise in the evening and stand vertically up at night with their petioles in contact. But as the two cotyledons are of unequal height, they frequently interfere a little with each other's movements, the shorter one often not standing quite vertically. They awake early in the morning; thus at 6.45 A.M. on Nov. 27th, whilst if was still dark, the cotyledons, which had been vertical and in contact on the previous evening, were reflexed, and thus presented a very different appearance. It should be borne in mind that seedlings in germinating at the proper season, would not be subjected to darkness at this hour in the morning. The above amount of movement of the cotyledons is only temporary, lasting with plants kept in a warm greenhouse from four to six days; how long it would last with seedlings growing out of doors we do not know.