OF FISHES IN GENERAL. 



245 



stomach of all creatures, which we can neither 

 describe nor define, converting the substances 

 they swallow into a fluid fitted for their own 

 peculiar support. This is done neither by 

 trituration, nor by warmth, nor by motion, 

 nor by a dissolving fluid, nor by their united 

 efforts ; but by some principle in the stomach 

 yet unknown, which acts in a different man- 

 ner from all kinds of artificial maceration. 

 The meat taken into the stomach or maw is 

 often seen, though very near being digested, 

 still to retain its original form, and ready 

 for a total dissolution, while it appears to the 

 eye as yet untouched by the force of 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 are ever craving. 



Yet though fish are thus hungry, and for 

 ever prowling, no animals can sutler 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 sustenance. 

 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 animals 

 the most voracious and insatiable. Whatever 

 any of them is able to swallow, possessed of 

 life, seems to be considered as the most desir- 

 able food. Some that have very small mouths 

 feed upon worms and the spawn of other fish ; 

 others, whose mouths are larger, seek 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 fierce op- 

 position, when the fish with the largest swallow 

 comes off with the victory and devours its an- 

 tagonist. 



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 shal- 

 lows where the greater are unable, or too 

 heavy to pursue. There they become inva- 

 ders in turn, and live upon the spawn of lar- 

 ger fish, which they find floating upon the 

 surface of the water ; yet there are dangers 

 attending them in every place. Even in the 

 shallows, the mussel, the oyster, and the scal- 

 lop, lie in ambush at the bottom, with tlieir 

 shells open, and whatever little fish inadver- 

 tently approaches into contact, they at once I 



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 cachelot 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 sum- 

 mer, 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 contrary, 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, breathe 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 being 

 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 sub-adjacent 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 breathe 

 swifter, and with greater difficulty ; it will 

 then be seen to rise towards the surface, to 

 get more air ; the bubbles on its surface begin 

 to disappear ; the belly, that was before swol- 

 len, will then fait of a sudden ; and the ani- 

 mal sinks expiring and convulsed at the 

 bottom. 



