532 THE OCEAN WORLD. 
however, of the imperfect structure of their ears, fishes are sensible 
to the least noise. In consequence, silence is a rigorous law with 
fishermen. 
The dimensions of the mouth and teeth are very variable in 
fishes; these organs are in proportion to their voracity, which in many 
of these beings is very great. The form and development of the 
buccal pieces are also very various. Some species are toothless, but 
in most fishes the teeth are very numerous. They are sometimes 
attached, not alone to the two jaws, but also to the palate, to the 
tongue, and upon the interior of the branchial arches, and even in 
the back mouth, that is to say, upon the pharyngeal portions, which 
surround the entrance to the cesophagus. | 
The form of their teeth is very variable, both in arrangement and 
position : some are in the form of an elongated cone, either straight 
Fig. 354.—Teeth of the Trout. Fig. 355.—Teeth of the Gold-fish Dorada. 
or curved. When small and numerous, they are comparable to the 
points of the cards used in carding wool or cotton. Sometimes they 
are so slender and dense as to resemble the piles of velvet, and often, 
from their very minute size, their presence is more easily ascertained 
by the finger than the eye. In some members of the Salmonidz, for 
instance, we find a row of teeth on the bone that forms the middle 
ridge of the palate, which is called the vomer. On each side of 
this is another row on the fadatine bones, and outside these is a third 
pair of rows on the upper jaw-bones. Some fishes have flat teeth, 
with a cutting edge in front of the jaws, like a true incisor; others 
have them rounded or oval, adapted to bruise or crush the various 
substances on which they feed. 
The cesophagus, connected with the mouth, is short in fishes ; the 
stomach and intestines vary in form and dimensions. Digestion is 
very rapid with these beings. Most of them feed on flesh, but there 
are a few where the mouth is without teeth, which feed on vegetables. 
The growth of fishes is slow or very rapid, according to the abun- 
dance of food ; they can suffer a very long fast, but in that state they 
