The Cow tree, or Palo de Vacca (_Galactodendron utile_), appears nearly allied to the Bread-fruit tree, though its flowers are unknown. The nut, however, which is covered with a husk apparently composed of the hardened calyx, resembles those of the other plants belonging to the Urticaceæ, and the bark when wounded gives out abundance of milk, which is good to drink. Humboldt in his _Relation Historique_, describes this tree as “growing on the sides of the rocks, its thick roots scarcely penetrating the stony soil, and unmoistened during many months of the year by a drop of rain or dew. But dry and dead as the branches appear,” Humboldt continues, “if you pierce the trunk, a sweet and nutritive milk flows forth, which is in the greatest profusion at day-break. At this time the blacks, and other natives of the neighbourhood, hasten from all quarters, furnished with large jugs to catch the milk, which thickens and turns yellow on the surface. Some drink it on the spot, others carry it home to their children; and you might fancy you saw the family of a cowherd gathering around him, and receiving from him the produce of his kine.” (_Humboldt, as quoted in the Botanical Magazine_, vol. 66, t. 3724.) [Illustration: FIG. 75.—UPAS TREE.] The Upas, or Poison tree of Java (_Antiaris toxicaria_), about which so many fabulous stories have been told, belongs to this tribe. The male flowers are gathered together in small heads on a fleshy receptacle, (see _fig._ 75 _a_;) and each consists of a calyx of four sepals (_b_), bending over four stamens, with long anthers and very short filaments. The female flowers have an undivided fleshy calyx with two styles, and this fleshy covering forms the pericardium of the fruit, which is a drupe. When ripe, the fruit represents a moderately sized plum, inclosing the nut, or stone, which contains the kernel or seed. The poison lies in the milky sap. [Illustration: FIG. 76.—MULBERRY.]