INTRODUCTION AND BREEDING OF FISH. 97 
Introduction and Breeding of Fish. 
The introduction and successful breeding of fish or roreign 
species appears to have been long practised in China, and was 
not unknown to the Greeks and Romans.* This art has been 
revived in modern times, but thus far without any important 
results, economical or physical, though there seems to be good 
reason to believe it may be employed with advantage on an 
extended scale. As in the case of plants, man has sometimes 
undesignedly introduced new species of aquatic animals into 
countries distant from their birthplace. The accidental escape 
of the Chinese goldfish from ponds where they were bred as a 
garden ornament, has peopled some European, and it is said 
American streams with this species. Canals of navigation and 
irrigation interchange the fish of lakes and rivers widely sepa- 
rated by natural barriers, as well as the plants which drop 
their seeds into the waters. The Erie Canal, as measured by 
its own channel, has a length of about three hundred and sixty 
miles, and it has ascending and descending locks in both diree- 
tions. By this route, the fresh-water fish of the Hudson and 
the Upper Lakes, and some of the indigenous vegetables of 
these respective basins, have intermixed, and the fauna and 
flora of the two regions have now more species common to both 
than before the canal was opened.t The opening of the Suez 
Canal will, no doubt, produce very interesting revolutions in 
the animal and vegetable population of both basins. The 
Mediterranean, with some local exceptions—such as the bays of 
Calabria, and the coast of Sicily so picturesquely described by 
* The observations of COLUMELLA, de Re Rustica, lib. viii., sixteenth aud 
following chapters, on fish-breeding, are interesting. The Romans not only 
stocked natural but constructed artificial ponds, of both fresh and salt water, 
and cut off bays of the sea for this purpose. They also naturalized various 
species of sea-fish in fresh water. 
+ The opening or rather the reconstruction of the Claudian emissary by 
Prince Torlonia, designed to drain the Lake Fucinus, or Celano, has introduced 
the fish of that lake into the Liri or Garigliano which receives the discharge 
from the lake.—DororEs, Sommurio storico del? Alieutica, p. 60. 
