The spurges or Euphorbiaceæ constitute the most important group in reference to the amount of caoutchouc contained. From the Port of Para in South America, from Guiana, and the neighboring states, an incredible quantity of India-rubber is shipped for Europe, and this is principally obtained from a large tree growing in those regions, called the Siphonia elastica. That beautiful tree, the Siphonia, is about sixty feet high, and has a smooth brownish-gray bark, in which the Indians make long and deep incisions down to the wood, from whence the white juice then abundantly flows forth. Many other plants of this group contain caoutchouc, but from none is it so easy to obtain in large quantity. Though the sap of Siphonia is at least harmless, though the juice of the Tabayba dolce (Euphorbia balsamifera) is even similar to sweet milk and, thickened into a jelly, eaten as a delicacy by the inhabitants of the Canary Islands, as Leopold von Buch relates in his interesting description of the Canaries; yet most of the plants of this group are to be counted among the suspicious, or even most actively poisonous, on account of this very juice. And yet, strangely enough, they also furnish a most wholesome food, which we have scarcely anything to compare with. Throughout all the hotter part of America the culture of the mandioc-root (Jatropha Manihot) is one of the most important branches of husbandry. The native savages and the Europeans, the black slave and free man of color alike substitute for our white bread and rice the tapioca and the Mandiocca farinha, or Cassava-meal, and the cakes prepared from it (_pan de tierra caliente_ of the Mexicans). The sweet yucca (Yuca dulce), which is the name applied there to the mandioc plant, must be distinguished from the sour or bitter kind (Yuca amara). The former, which is therefore cultivated with great care, may be eaten at once without danger; while the latter, eaten fresh, is an active poison. They serve the uncivilized son of the South American tropics for food. The sated savage saunters round to seek a new sleeping-place, but woe to him! inadvertently he has prepared his couch beneath the dreadful manchineel (Hippomane Mancinella), and in a sudden shower the rain drips from its leaves upon him. In frightful pain he wakes up, covered with blisters and ulcers, and if he escapes with life, he is at least the richer of a fearful experience of the poisonous properties of the Euphorbiaceæ. But this will seldom happen to a native; the manchineel is avoided in America with the same mysterious and almost superstitious awe as the fabulous poison-tree in Java. Happily, the trumpet-tree (Bignonia leucoxylon), the sap of which is the surest antidote against the manchineel, usually rears its beautiful purple blossoms close at hand, the constant companion of that dangerous Euphorbiacean.