Schweinfurth, in his "Heart of Africa," describes what may be termed an insect organ-builder. In the country of the Shillooks, he says, the acacia groves extend over an area of a hundred miles square and stretch along the right bank of the stream. From the attacks of larvæ of insects, which have worked to the inside, their ivory white shoots are often distorted in form and swollen out at their base with globular bladders measuring about an inch in diameter. After the mysterious insect has unaccountably managed to glide out of its circular hole, this thorn-like shoot becomes a sort of musical instrument, upon which the wind, as it plays, produces the regular sound of a flute. On this account the natives of the Soudan have named it the whistling tree. _Aconite._ This plant was regarded by the ancients as the most violent of poisons. They said that it was the invention of Hecate, and that it sprung from the foam of Cerberus. _Oysters Growing on Trees._ Mr. C. H. Williams, of the Geographical Society of England, tells us how oysters inhabit the Mangrove woods in Cuba: "For several years I resided in that island, and have several times come across scenes and objects which many people would consider great curiosities—one in particular. Oysters grow on trees, in immense quantities, especially in the southern part of the island. I have seen miles of trees, the lower stems and branches of which were literally covered with them, and many a good meal have I enjoyed with very little trouble in procuring it. I simply placed the branches over the fire, and, when opened, I picked out the oysters with a fork or a pointed stick. These peculiar shell-fish are indigenous in lagoons and swamps on the coast, and as far as the tide will rise and the spray fly so will they cling to the lower parts of the Mangrove trees, sometimes four or five deep, the Mangrove being one of the very few trees that flourish in salt water." _The Shaking Aspen._ The aspen is popularly said to have been the tree which formed the cross upon which the Saviour was crucified, and since then its boughs have been filled with horror and tremble ceaselessly. Unfortunately for the probability of this story, the shivering of the aspen in the breeze may be traced to other than a supernatural cause. The construction of its foliage is particularly adapted for motion; a broad leaf is placed upon a long footstalk so flexible as scarcely to be able to support the leaf in an upright posture. The upper part of this stalk, on which the play or action seems mainly to depend, is contrary to the nature of footstalks in general, being perfectly flattened, and, as an eminent botanist has acutely observed, is placed at a right-angle with the leaf, being thus particularly fitted to receive the impulse of every wind that blows. _Tree Planting in Java._ In Java a fruit tree is planted on the birth of each child, and is carefully tended as the record of his or her age.