THE CATFISH OR BULLHEAD 
HEN we study fish, we should try to 
understand how they are adapted by 
form and color for the peculiar place 
where they live. Any of the catfish 
are good examples of adaptation 
of form to life. The most com- 
mon of the catfish is, probably, the bullhead, and 
it illustrates this principle well. It is mud-colored, 
and has no scales; since it lives in the mud it does 
not need scales to protect it. The skin is very thick 
and leathery, and not easily broken. The general 
shape of the front of the body is flat, and the bull- 
head is thus fitted for groping about the muddy bot- 
toms of streams. The pectoral fins open out on the 
same plane as the body, and are weapons of defense, 
since the sharp tips of their spines punish whatever 
touches them. 
Bullheads’ eyes are oval, and rimmed with a nar- 
row band of pale yellow; they are prominent; so 
that when moved backward and forward they com- 
mand a view of the enemy in the rear or at the front, 
while the fish remains motionless; but after all, eyes 
are not much good to a fish that gropes in the mud 
for food, and the bullhead has developed barbels 
or feelers about the mouth, which assist in searching 
for food. Two of these barbels stand upright and 
give news of anything above; the large ones, one on 
either side of the mouth, are the most useful of all, 
and are kept constantly moving for new sensations. 
The barbels below the mouth give information as to 
the nature of things below them. The bullhead 
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