168 ANIMAL FORMS 
ored like the bottom—sand colored or brown or black—and 
the under side is white. When the flounder is first hatched, 
the eyes are on each side of the head, and the animal 
swims upright in the water like other fishes. But it soon 
rests on the bottom; it turns to one side, and as the body 
is turned over the lower. eye begins to move over to the 
other side. Finally, we may close the series with the an- 
glers (Fig. 105), in which the first dorsal spine is trans- 
formed into a sort of fishing-pole with a bait at the end, 
which may sometimes serve to lure the little fishes, which are 
soon swallowed when once in reach of the capacious mouth. 
162. Internal anatomy.—A few fishes are vegetarians, but 
the greater number are carnivorous. Some swallow large 
quantities of sand of the sea-bottom and absorb from it the 
small organisms living there. Others are provided with 
beaks for nipping off corals and tube-dwelling worms. Huge 
plate-like teeth enable others to crush mollusks, sea-urchins, 
and crabs, and many are adapted for preying upon other 
fishes. The latter are often able to escape, owing to the 
presence of numerous spines, sometimes supplied with 
poison-glands; or their colors are protective, and a vast 
number of devices are present which enable them with 
some degree of surety to escape their enemies and capture 
food. 
Usually, without mastication, the food passes into the 
digestive tract (Fig. 106), which in the main resembles that 
of the squirrel, but varies considerably according to the 
nature of the food it is required to absorb. As in other 
animals, it is usually longer in the vegetable feeders. In 
most fishes the walls of the canal are pushed out at the 
junction of the stomach and intestine, to form numerous 
processes like so many glove-fingers (the pyloric ceca, Fig. 
106, py.c.), which probably serve to increase the absorptive 
surface. The same result is obtained in other ways, chiefly 
by numerous folds of the lining of the canal. 
The blood-system is much more complex in the fishes 
