This fruit is at first green, but when ripe, it assumes a dull yellow colour; and the flesh is spongy and very white. Its size and shape are so varied, that it would be impossible to describe them; sometimes it has a long slender part next the stalk, like the neck of a bottle; sometimes it is swollen, and sometimes of great length, and of form so curved as to be shaped almost like a bugle horn, or the musical instrument called a serpent. So hard and strong is the _rind_ of the bottle-gourd, that this, when freed from the pulp, is frequently converted by the Americans, as well as the inhabitants of the West Indies, into drinking cups, flagons, bottles, and other domestic utensils; but, on being first used, it communicates a disagreeable taste to the juices contained in it. The _pulp_, boiled with vinegar, is sometimes eaten. 227. _The WATER MELON_ (Cucurbita citrullus) _is a roundish or oblong species of gourd, with thin smooth rind, marked with star-like spots, the leaves deeply divided into lobes, and the flowers somewhat resembling those of the cucumber._ Persons who have visited hot climates know well how to appreciate the grateful coolness and delicious flavour of the water melon, the flesh of which is so succulent that it melts in the mouth; and the central pulp of which is fluid, like that of the cocoa-nut, and may be sucked, or poured out through a hole in the rind, and thus made to afford a most refreshing beverage. To the inhabitants of Egypt, China, the East Indies, and other countries, where they are cultivated to a great extent, water melons are extremely valuable, both as food and physic. They are allowed to be eaten in fevers, and other inflammatory complaints. Their flesh or pulp is, in general, of reddish colour; one kind, however, called by the French _pastèque_, has a whitish green pulp. The latter are frequently pickled in vinegar, like gerkins; and are eaten in fricassees, or baked in sweet wine. Both these varieties may be grown in our gardens, under hot-bed frames, in the same manner as cucumbers. TETRANDRIA. 228. _The BIRCH_ (Betula alba) _is a forest-tree, easily known by the smooth appearance and silvery colour of its bark, by its leaves being somewhat triangular, but acute, their smallness in comparison with those of other timber trees, and by the small branches being slender and flexible._