100 INTRODUCTION AND BREEDING OF FISH. 
ticular branch of what is called, not very happily, pisctewlture, 
has not yet established its claims to the attention of the physi- 
cal geographer or the political economist, the artificial breed- 
ing of domestic fish, of the lobster and other crustacea, has 
already produced very valuable results, and is apparently des- 
tined to occupy an extremely conspicuous place in the history 
of man’s efforts to compensate his prodigal waste of the gifts of 
nature. The arrangements for breeding fish in the Venetian 
lagoon of Comacchio date far back in the Middle Ages, but the 
example does not seem to have been followed elsewhere in 
Europe at that period, except in small ponds where the pro- 
pagation of the fish was left to nature without much artificial 
aid. The transplantation of oysters to artificial ponds has 
long been common, and it appears to have recently succeeded 
well on a large scale in the open sea on the French coast. A 
great extension of this fishery is hoped for, and it is now pro- 
posed to introduce upon the same coast the American soft 
clam, which is so abundant in the tide-washed beach sands of 
Long Island Sound as to form an important article in the diet 
of the neighboring population. Experimental pisciculture has 
been highly successful in the United States, and will probably 
soon become a regular branch of rural industry, especially as 
Congress, at the session of 1871-2, made liberal provision for 
its promotion. 
The restoration of the primitive abundance of salt and fresh 
water fish, is perhaps the greatest material benefit that, with 
our present physical resources, governments can hope to confer 
upon their subjects. The rivers, lakes, and seacoasts once 
restocked, and protected by law from exhaustion by taking fish 
at improper seasons, by destructive methods, and in extravagant 
quantities, would continue indefinitely to furnish a very large 
supply of most healthful food, which, unlike all domestic 
and agricultural products, would spontaneously renew itself 
and cost nothing but the taking. There are many sterile or 
wornout soils in Europe so situated that they might, at no very 
formidable cost, be converted into permanent lakes, which 
