- [Footnote: This vital heat disappeared at night, but was not prevented
by placing the plants in the dark during the day-time.
A yet more striking physiognomic contrast than that of Casuarineæ, Needle trees, and the almost leafless Peruvian Colletias, with Aroideæ, is presented by the comparison of those types of the greatest contraction of the leafy organs with the Nymphæaceæ and Nelumboneæ. We find in these as in the Aroideæ, leaves, in which the cellular tissue forming their surface is extended to an extreme degree, supported on long fleshy succulent leaf-stalks; as in Nymphæa alba; N. lutea; N. thermalis (once called N. lotus, from the hot spring of Pezce near Groswardein, in Hungary); the species of Nelumbo; Euryale amazonica of Pöppig; and the Victoria Regina discovered in 1837 by Sir Robert Schomburgk in the River Berbice in British Guiana, and which is allied to the prickly Euryale, although, according to Lindley, a very different genus. The round leaves of this magnificent water plant are six feet in diameter, and are surrounded by turned up margins 3 to 5 inches high, light green inside, and bright crimson outside. The agreeably perfumed flowers, twenty or thirty blossoms of which may be seen at the same time within a small space, are white and rose coloured, 15 inches in diameter, and have many hundred petals. (Rob. Schomburgk, Reisen in Guiana und am Orinoko, 1841, S. 233.) Pöppig also gives to the leaves of his Euryale amazonica which he found near Tefe, as much as 5 feet 8 inches French, or 6 English feet, diameter. (Pöppig, Reise in Chile, Peru und auf dem Amazonenstrome, Bd. ii. 1836, S. 432.) If Euryale and]*
