Professor John Phillips, alluding to the theories which have been given of the mode in which Molluscs bore into the rocks in which they live, believes that an exclusively mechanical theory will not account for the phenomenon; and he is inclined to adopt the view of Dr. T. Williams--that the boring of the Pholades can only be explained on the principle which involves a chemical as well as a mechanical agency. Mr. E. Ray Lankester notices that the boring of Annelids seems quite unknown; and he mentions two cases, one by a worm called Leucadore, the other by a Sabella. Leucadore is very abundant on some shores, where boulders and pebbles may be found worm-eaten and riddled by them. Only stones composed of carbonate of lime are bored by them. On coasts where such stones are rare, they are selected, and others are left. The worms are _quite soft_, and armed only with horny bristles. _How, then, do they bore?_ Mr. Lankester maintains that it is by carbonic acid and other acid excretions of their bodies, _aided_ by the mechanical action of their bristles. The selection of a material soluble in these acids is most noticeable, since the softest chalk and the hardest limestone are bored with the same facility. This can only be by chemical action. If, then, we have a case of chemical boring in these worms, is it not probable that many Molluscs are similarly assisted in their excavations? FOOTNOTES: [27] How Brunel took his construction of the Thames Tunnel from observing the bore of the _Teredo navalis_ in the keel of a ship, in 1814, is well known. [28] "Athenæum," No. 1640. [29] See also "Life in the Sea," in "Strange Stories of the Animal World," by the author of the present volume. Second Edition. 1868. INDEX. ANCIENT Zoological Gardens, 12 Animals, Rare, of London Zoological Society, 16, 17, 18 Annelids, boring, 348 Annelids and Molluscs, Boring Habits of, 348 Ant-Bear in captivity, 76 Ant-Bear, the Great, 72 Ant-Bear at Madrid, 72 Ant-Bear described, 77 Ant-Bear, Domestic, in Paraguay, 75 Ant-Bear, Economy of, 76 Ant-Bear and its Food, 74 Ant-Bears, Fossil, 80, 81 Ant-Bear, Muscular Force of, 79 Ant-Bear, Wallace's Account of, 73 Ant-Bear, Zoological Society's, 76, 82, 84 Ant-Eater, Porcupine, 84 Ant-Bear, Professor Owen on, 80 Ant-Eaters, scarcity of, 80 Ant-Eater, Tamandua, 82 Ant-Eaters, Von Saek's Account of, 83 Aristotle's History of Animals, 279, 280 BARNACLE GEESE, finding of the, 334 Barnacle Goose, Gerarde on, 332 Barnacle Goose, Giraldus Cambrensis on, 332 Barnacle Goose, Max Müller on, 331 Barnacle Goose, name of, 332 Barnacle Goose, Sir E. Tennent on, 334 Barnacle Goose, Sir Kenelm Digby on, 334 Barnacle Goose, Sir R. Moray on, 331 Barnacle Goose, Stories of the, 331-335 Barnacles breeding upon old ships, 333 Barnacle Geese in the Thames, 331 Bat, altivolans, by Gilbert White, 100 Bat, American, by Lesson, 91