206 THE INHABITANTS OF THE SEA. 
escaping from the pursuit of the bonitos and albacores, often, 
however, leads to their destruction in another element, where 
gulls and_ frigate- 
birds frequently 
seize them with 
lightning-hke ra- 
pidity, ere they fall 
back again into the 
ocean. It is amus- 
ing to observe a 
bonito swimming 
beneath the feeble 
aéronaut, keeping 
him steadily in view, and preparing to seize him at the moment 
of his descent. But the flying-fish often eludes the bite of his 
enemy, by instantaneously renewing his leap, and not unfre- 
quently escapes by extreme agility. 
The specific gravity of the flying-fish can be most admirably 
regulated in correspondence with the element through which it 
may move. The swim-bladder, when distended, occupies nearly 
the entire cavity of the abdomen, thus containing a large volume 
of air; and in addition to this, there is a membrane in the 
mouth which can be inflated through the gills. The pectoral 
fins, though so large when expanded, can be folded into an 
exceedingly slender, neat, and compact form, so as to be no 
hindrance to swimming. A light displayed from the chains 
of a vessel in a dark night, will bring many flying-fishes on 
board, where they are esteemed as a great delicacy. Their 
fate, thus to be persecuted in both elements and to find security 
nowhere, has often been pitied in prose and verse; but although 
they excite so much sentimental commiseration, they are them- 
selves no less predaceous than their enemies, feeding chiefly on 
smaller fishes. 
The flying-fish of the West Indian waters is frequently 
allured by the tepid waters of the Gulf-stream into higher lati- 
tudes, and Pennant cites several examples of its having been 
found near the British coast. 
The Flying-Gurnard (7vrigla volitans) of the Mediterranean, 
Atlantic, and Indian seas, a highly singular and beautiful species, 
also raises itself into the air by means of its large pectoral fins, 
