16 CANARY ISLANDS. 



rekindled by passing the dry hand over it ; but when the 

 light is a second time extinguished it cannot be repro- 

 duced."* These animals are supposed to constitute the 

 chief food of cetaceous fish. 



I observed another beautiful class of animals floating 

 down the Gulf, called by seamen, the Portuguese man-o- 

 war (PliJ/saUa jidagica. Lam.) They resemble an ob- 

 loncr bladder, elevated superiorly into an oblique and 

 wrinkled crest, and furnished beneath, near one of the 

 extremities, with a variety of cylindrical, fleshy productions, 

 terminated at different lengths, which unite with the body. 

 They float at will, upon the surface of the water, most fre- 

 quently when it is calm, employing the crest for a sail ; 

 and when quietly gliding along, the rays of the sun drop 

 upon them, and produce a beautiful irridescent appear- 

 ance. By touching these animals with the hand, they dis- 

 charge, as a means of defence, a gaseous fluid, which stings 

 and burns like the sea-nettle. They are found in all 

 tropical seas. 



On the morning of the 14th instant, thousands of flying- 

 fish (Exocetus volitans. Lin.) were seen darting through 

 the air in a direct line opposite to the waves. These fish 

 seem to lead the most miserable existence. In their own 

 element, they are incessantly pursued by dolphins and 

 other fish of prey. If they endeavor to avoid them by hav- 

 ing recourse to the air, they either meet their fate from 

 gulls or other predatory birds, or are forced down the 

 mouths of the inhabitants of the deep, which keep pace 

 below with their aerial excursions. The head of this fish 

 is scaly, their body whitish, and their belly angular. Their 

 pectoral fins are very large, which enable them to raise 

 themselves from the water, and fly to a considerable dis- 

 tance, till their fins become dry, and then they descend 

 into the water. They are sometimes found in northern 

 seas, but are the most common between the tropics. When 

 taken, they serve for excellent food. 



In calm weather, I have constantly seen the pilot-fish 

 (Gasterosteus ductor. Lin.) at our stern. These fish 



* Humboldt. 



