With regard to the alleged co-operation of the threshing and sword-fish in the destruction of whales, all that can be said is that the statements, although antecedently improbable, are sufficient in number not to be ignored. Mr. Day appears to accept the evidence as adequate, and gives the following cases:-- Captain Arn, in a voyage to Memel in the Baltic, gives the following interesting narrative:--One morning during a calm, when near the Hebrides, all hands were called up at 2 A.M. to witness a battle between several of the fish called threshers or fox-sharks (_Alopecias vulpes_), and some sword-fish on one side, and an enormous whale on the other. It was in the middle of the summer; and the weather being clear, and the fish close to the vessel, we had a fine opportunity of witnessing the contest. As soon as the whale's back appeared above the water, the threshers springing several yards into the air descended with great violence upon the object of their rancour, and inflicted upon him the most severe slaps with their long tails, the sounds of which resembled the reports of muskets fired at a distance. The sword-fish in their turn attacked the distressed whale, stabbing from below: and thus beset on all sides and wounded, when the poor creature appeared, the water around him was dyed with blood. In this manner they continued tormenting and wounding him for many hours, until we lost sight of him; and I have no doubt they in the end completed his destruction. The master of a fishing-boat has recently observed that the thresher-shark serves out the whales, the sea sometimes being all blood. One whale, attacked by these fish, once took refuge under his vessel, where it lay an hour and a half without moving a fin. He also remarked having seen the threshers jump out of the water as high as the mast-head and down upon the whale, while the sword fish was wounding him from beneath, the two sorts of fish evidently acting in concert. FOOTNOTES: [110] _Phil. Frags._, translated by Huxley, _Taylor's Mag._, 1853, p. 196. [111] Silliman's _American Journal_, Feb. 1872. [112] Ransom, _Ann. and Mag. Nat. Hist._, 1865, xvi., p. 449. [113] Quoted from Francis Day, F.L.S., 'Instincts and Emotions of Fish,' _Journ. Linn. Soc._, vol. xv., pp. 36-7, where see for other cases of nest-building among fish. [114] _Ibid._ [115] Kaup, _Catal. Lopho. Fish in Brit. Mus._ 1856, p. i. [116] Yarrell, _Brit. Fishes_, 2nd ed. ii. p. 436. [117] _Compt. Rend._, Nov. 4, 1872, p. 1127. [118] _Phil. Trans. Royal Society_, 1747. [119] F. Day, _loc. cit._ [120] Shelley, _Lines written in the Bay of Lerici_. [121] See Smiles, _Lives of Engineers_, vol. iii., p. 69. [122] See 'On the Jaculator-Fish,' by Schlosser, _Phil. Trans._ 1764.