THE SHORES OF BRITAIN. 83 
change in their depth of water, have the ventral fins 
placed far back on the belly, as the Herring and the 
Salmon ; while those which feed at the bottom in deep 
water, but yet have considerable power of swimming, 
such as the Cod, require the ventrals to be situated 
near the head, sometimes even in advance of the pec-' 
torals, in order to act with rapidity and effect upon 
the fore part of the body, which is usually heavy in 
such fishes. The Flat-fishes and Skates, in which the 
ventrals are little developed, and the Hels, in which 
they are wanting, rarely quit the ground, but grovel 
on the mud in shallow water. Many fishes have cer- 
tain spines of the fins developed into stiff and for- 
midable weapons, and others have equally effective 
armour placed upon the gill-covers, the sides of the 
body or the tail. With these, which are usually 
jointed, and which the fish has the power of erecting 
stiffly, and of directing with considerable precision, it 
sometimes inflicts severe wounds on the incautioug 
fisherman, as well as on its opponent, in the battles 
with its own kind, which often occur. The little 
Stickleback (Gasterosteus), which abounds all round 
the coast, as well as in our fresh waters, is armed 
with sharp spines on the back’ and sides, which it 
wields like a perfect tyrant. “When a few are fifst 
turned into a tub of water, they swim about in a 
shoal, apparently exploring their new habitation. 
Suddenly one will take possession of a particular 
corner of the tub, or, as it will sometimes happen, of 
the bottom, and will instantly commence an attack 
upon his companions; and if any one of them ven- 
tures to oppose his sway, a regular and most furious 
