24 Fisuinc in AmerIcaAN WATERS. 
4s Dorsal 
Bd 
the sword-fish, Spanish mackerel, and the salmon are consid- 
ered the swiftest of the forked-tails; but the salmon has not, 
strictly speaking, a forked tail; it is more properly crescent- 
shaped. Of square-tails, the brook trout, squeteague, and 
Southern estuary trout are the swiftest swimmers. 
SECTION THIRD. 
GENERAL HABITS AND SENSES OF FISHES. 
Generally speaking, the principal habits and instincts of a 
majority of the finny armies consist in eating and protecting 
themselves from being eaten. The fact that over two thirds 
of the surface of the globe is covered by the sea, and that 
large parts of continents are covered by lakes, traversed by 
rivers, and occupied by marshes, proves the impossibility for 
man to have scanned with perspicacious eye the principal 
marked peculiarities of a majority of the familes which 
dwell deep down in the bosom of old ocean, however indus- 
trious he may have been in such research. 
Though the Chinese had understood fish culture many cen- 
turies, yet we date our practical knowledge of this art from 
A.D. 1837, when Mr. Shaw, of Scotland, expounded the theory 
in Blackwood under the head of “The transmutation of sal- 
mon,” and M. Gehen, of the Vosges, in France, began to culti- 
vate fish by artificial propagation. We now know that the 
difference in the species of fishes is no greater than is the di- 
versity of their habits. Some are solitary, and others grega- 
rious; some great wanderers, others restricted within narrow 
limits; some are surface-fecders, like the mackerel families, 
