432 FISHES. 



the fin being very low, whilst in others all the rays are 

 exceedingly elongate, so that the fin, when erected, projects 

 beyond the surface of the water. It is stated that Sword- 

 fishes, when quietly floating with the dorsal fin erect, can 

 sail before the wind, like a boat. 



Sword-fishes are the largest of Acanthopterygians, and 

 not exceeded in size by any other Teleostean ; they attain to 

 a length of from 12 to 15 feet, and swords have been obtained 

 more than three feet long, and with a diameter of at least 

 three inches at the base. The sword is formed by the pro- 

 longation and coalescence of the maxillary and intermaxillary 

 bones ; it is rough at its lower surface, owing to the develop- 

 ment of rudimentary villiform teeth, very hard and strong, 

 and forms a most formidable weapon. Sword-fishes never 

 hesitate to attack whales and other large Cetaceans, and by 

 repeatedly stabbing these animals generally retire from the 

 combat victorious. The cause which excites them to those 

 attacks is unknown ; but they follow this instinct so bliadly 

 that they not rarely attack boats or large vessels in a similar 

 manner, evidently mistaking them for Cetaceans. Sometimes 

 they actually succeed in piercing the bottom of a ship, 

 endangering its safety; but as tlrey are unable to execute 

 powerful backward movements they cannot always retract 

 their sword, which is broken off by the exertions of the fish 

 to free itself. A piece of a two-inch plank of a whale-boat, 

 thus pierced by a sword-fish, in which the broken sword stiU 

 remains, is preserved in the British Museum. 



The Eev. Wyatt Crill, who has worked as a missionary 

 for many years in the South Sea Islands, communicates that 

 young Sword-fishes are easily caught in strong nets, but no net 

 is strong enough to hold a fish of six feet in length. Speci- 

 mens of that size are now and then captured by hook and 

 line, a small fish being used as bait. Individuals with the 

 sword broken off are not rarely observed. Larger specimens 



