The most perfect and most familiar example is, perhaps, the common Hedgehog, which, when rolled up, displays an array of sharp points so judiciously disposed, that it fears but very few foes. The same may be said of the Australian Echidna, or Porcupine Ant-eater, and the Porcupine itself. Whether the radiating bristles of the larva of the Tiger-moth, commonly called the Woolly Bear, come under the same category, I cannot say, but think it very likely. Among vegetables the analogues are multitudinous. See, for example, the spikes of the Spanish and Horse Chestnuts, and especially the hair-like but formidable bristles which defend the common Prickly Pear. Indeed, all that tribe of plants is furnished so abundantly with natural ranjows, that a hedge of prickly pear forms the best defence which a house and garden can have. Another example of natural ranjows is seen in the Tree-caddis, one of which is shown in the illustration on page 108, as it appears when suspended from a twig. It is the work of one of the House-builder Moths of the West Indies, and forms a sort of house in which the caterpillar can rest securely. It is built of bits of twigs and thorns, the latter being disposed so that their points are outwards, much after the fashion of a hedgehog’s spines. I possess many specimens of Tree-caddis, evidently belonging to several species, and in all of them the principle is the same, _i.e._ a number of spikes set with their ends outwards in order to defend a central position. Sometimes these spikes are left exposed, as shown in the illustration, and sometimes they are covered with a slight but strong web. The principle, however, is the same in all. * * * * * NOW I shall have to use two very long words, and much against my will. I very much fear that, if most of my readers were to hear any one speak of the “repagula of Ascalaphus,” they would not be much the wiser. And yet there are no other words that can be used. In the first place, Ascalaphus is a name belonging to a genus of Ant-lions, remarkable for having straight, knobbed antennæ, very much like those of a butterfly. This insect deposits its eggs in a double row on twigs, and then defends them with a series of natural ranjows, set in circular rows, and supposed to be without analogies in the animal creation. They are transparent, reddish, and “are expelled by the female with as much care as though they were real eggs, and are so placed that nothing can approach the brood; nor can the young ramble abroad until they have acquired strength to resist the ants and other insect enemies.” The word “repagulum,” by the way, signifies a bar or barrier. A turnpike gate when closed would be a repagulum, and so would a chevaux-de-frise. TEARING WEAPONS.