FISH IN GENERAL. 37 



after a space return again, acquire the powers of alternating 

 their stations nearer the surface and sinking to repose at 

 remoter distances from the operation of some action not un- 

 connected with heat ; and therefore their retreats are probably 

 not far beneath the known superficial currents of the sea, and 

 confined to the recesses of the shelving bases of continents, 

 islands, and submarine elevations ; there they may grovel in 

 inaction, or perhaps hang suspended in a blind and torpid 

 equilibrium, till a solstitial day or increasing warmth on 

 either hemisphere, or the periodical changes of a monsoon, 

 stimulating their organs into new excitement, recommences 

 the period of activity K 



The business of gregarious fishes, such as approach the 

 shores periodically, appears to be confined to spawning, or 

 feeding upon some particular bait, or both. Among these, 

 the gadoid and clupeoid families advance from polar and 

 temperate latitudes towards the equatorial seas : while the 

 mugiloid and scomberoid tribes take a contrary direction, 

 from the warmer latitudes towards the temperate seas. But 



1 A fact which I witnessed in 1797, about the latitude of 19 N. nearly 

 midway between Africa and America, seems to countenance this period- 

 ical blindness. An ill-contrived experiment having been made to ascertain 

 the temperature of the sea at a great depth, with a deep sea lead, and 

 300 fathoms of line fastened to a bottle, the line became entangled, and 

 was supposed to have floated, for on hauling up, a fish of the scomber 

 family was found encumbered in a coil, but remarkable, because although 

 he was sound and firm, both eyes were nearly closed from the nose back- 

 ward by a white film or nictitating membrane, and the jaws were fixed 

 close, so as to be opened with great difficulty. A Malay seaman on board 

 said it was not an uncommon occurrence in the East India Seas, and 

 indicated the torpid period of the species, when they do not take the bait, 

 and sink to depths beyond soundings. I doubt that any species of fish 

 in a state of activity can exist without the occasional aid of atmospheric 

 air. The account of soundings below 1000 fathoms may be doubted, 

 though 2000 fathoms of line might be out. C. H. S. 



