the Residence of certain Fishes. 231 
cient supply of food. In many cases, perhaps, we may judge for 
them; and if the proprietor of a Highland lake chooses to eat cod 
rather than pike, at the expense of a proportion of his perch and 
trout, and can persuade them to live in his fresh water, it is 
probable that they will not have to lament. the want of food. 
In any case, our ignorance on this subject need not be a bar in 
the way of any experiment on this kind of naturalization. So 
many species find their food without our knowing the means or the 
materials, that we may safely trust to their wants and their powers. 
Besides, as the enormous reproduction of all these tribes is evi- 
dently in part destined for the general support in succession of all 
those of which they are the prey, it is evident that by increasing 
the population and the variety in any of these watery kingdoms, 
we increase the means of mutual support. The smaller feed on 
that which the larger could not find or use; and thus they maintain 
the existence of their superiors, who, in return, are destined per~ 
haps to maintain them with their own ova or offspring. If again, 
practically, the plaice and the flounder, natives of the sea, have 
found the means of permanently feeding themselves in fresh waters, 
it is not unlikely that many others may there. find food unknown 
to us, and, for want of trial, unknown at present even to them. 
But there is no difficulty in feeding tem, should that prove ne- 
cessary. This was a common practice with the Romans; and 
those who choose to turn to Varro or Columella, may see records 
of the immense sums which were expended by the Romans in feed- 
ing the fish in their vivaria; as they may also see, from the enor- 
mous prices paid by Cesar, Lucullus, and others, to what an-ex- 
tent the practice of keeping fish-ponds was carried, and how im- 
portant a branch of rural economy this was considered. The con~ 
sequence attached to fishes by this people is apparent everywhere ; 
and no one need be told of the celebrated Senatusconsultum held 
on aturbot, or of the fishes which, Martial tells us, came to their 
owner’s call and licked his hands. If, in our own rural. economy, 
it is found profitable to feed pigs and fowls, it would not be less so 
to feed fish, nor are these tribes, apparently, less omnivorous than 
hogs. 
Vor. VII. R 
