FISHES. 
9 
which, are endowed with swiftness in swimmings 
the tail-fin is forked, each division being pointed, 
as are also the pectorals ; while in those of slug- 
gish habits, the caudal, as well as the pectorals, 
is commonly short, even, or rounded. It is by 
the force of the powerful strokes given obliquely 
right and left upon the water by this fin that the 
HADDOCK. 
fish is urged onward in swift swimming ; the 
pectorals and ventrals seem little used to commu- 
nicate motion, except it be in deliberate change 
of place, for very short distances, or for turning ; 
their chief use seems to be that of balancing the 
body. ^ 
The bones are less dense and compact in their 
structure than those of the preceding Classes; 
