FISHES IN GENERAL. 



609 



the stomach. This animal power is lodged 

 in the maw of fishes, in a greater degree than 

 in any other creatures ; their digestive powers 

 are quick, and their appetites ever are craving. 



Yet though fish are thus hungry, and for 

 ever prowling, I10 animals can suffer the want 

 of food for so long a time. The gold and 

 silver fish we keep in vases, seem never to 

 want any nourishment at all : whether it be 

 that they feed on the water insects, too minute 

 for our observation, or that water alone is a 

 sufficient supply, is not evident ; but they are 

 often seen for months without apparent suste- 

 nance. Even the pike, the most voracious of 

 fishes, will live in a pond where there is none 

 but himself; and, what is more extraordinary, 

 will be often found to thrive there. 



Still, however, fishes are of all other ani- 

 mals the most voracious and insatiable. What- 

 ever any of them is able to swallow, possessed 

 of life, seems to be considered as the most de- 

 sirable food. Some that have very small 

 mouths feed upon worms and the spawn of 

 other fish ; others, whose mouths are larger, 

 s?ek larger prey ; it matters not of what kind, 

 whether of another or their own. Those 

 with the largest mouths pursue almost every 

 thing that has life; and often meet each other 

 in fieiva opposition, when the fish with the 

 largest swallow comes off with the victory, 

 and devours its antagonist. 



Thus are they irritated by the continual 

 desire of satisfying their hunger ; and the life 

 of a fish, from the smallest to the greatest, is 

 but one scene of hostility, violence, and eva- 

 sion. But the smaller fry stand no chance in 

 the unequal combat ; and their usual way of 

 escaping is by swimming into those shallows 

 where the greater are unable, or too heavy, to 

 pursue. There they become invaders in turn, 

 and live upon the spawn of larger fish, which 

 they find floating upon the surface of the wa- 

 ter ; yet there are dangers attending them in 

 every place. Even in the shallows, the mus- 

 sel, the oyster, and the scallop, lie in ambush 

 at the bottom, with their shells open, and 

 whatever little fish inadvertently approaches 

 into contact, they at once close their shells 

 upon him, and devour the imprisoned prey at 

 their leisure. 



Nor is the pursuit of fishes, like that of ter- 

 restrial animals, confined to a single region, 

 or to one effort : shoals of one species follow 



those of another through vast tracks of ocean, 

 from the vicinity of the pole, even down to the 

 equator. Thus the cod, from the banks of 

 Newfoundland, pursues the whiting, which 

 flies before it even to the southern shores of 

 Spain. The cachalot is said, in the same 

 manner, to pursue a shoal of herrings, and to 

 swallow thousands at a gulp. 



This may be one cause of the annual mi- 

 gration of fishes from one part of the ocean to 

 the other ; but there are other motives which 

 come in aid of this also. Fishes may be in- 

 duced to change the place of their residence, 

 for one more suited to their constitutions, or 

 more adapted to depositing their spawn. It 

 is remarkable that no fish are fond of very 

 cold waters, and generally frequent those 

 places where it is warmest. Thus, in summer, 

 they are seen in great numbers in the shallows 

 near the shore, where the sun has power to 

 warm the water to the bottom ; on the con- 

 trary, in winter, they are found towards the 

 bottom in the deep sea ; for the cold of the 

 atmosphere is not sufficiently penetrating to 

 reach them at those great depths. Cold pro- 

 duces the same effect upon fresh-water fishes ; 

 and when they are often seen dead after 

 severe frosts, it is most probable that they 

 have been killed by the severity of the cold, 

 as well as by their being excluded by the ice 

 from air. 



All fish live in the water ; yet they all stand 

 in need of air for their support. Those of the 

 whale kind, indeed, breath air in the same 

 manner as we do, and come to the surface 

 every two or three minutes to take a fresh in- 

 spiration ; but those which continue entirely 

 under water, are yet under a necessity of be- 

 ing supplied with air, or they will expire in a 

 very few minutes. We sometimes see all 

 the fish of a pond killed, when the ice every 

 where covers the surface of the water, and 

 thus keeps off the air from the subjacent fluid. 

 If a hole be made in the ice, the fish will be 

 seen to come all to that part, in order to take 

 the benefit of a fresh supply. Should a carp, 

 in a large vase of water, be placed under an 

 air-pump, and then be deprived of its air, 

 during the operation a number of bubbles will 

 be seen standing on the surface of the fish's 

 body; soon after the animal will appear to 

 breath swifter, and with greater difficulty ; it 

 will then be seen to rise towards the surface, 



