Why is the gullet remarkably short in fishes ?

Because they have no neck. In some, indeed, the stomach seems to open directly into the mouth. The gullet is, however, capable of great extension, and when the stomach is unable to hold the whole of the prey, which has been seized, a part remains in the gullet until the inferior portion gives way. - Fleming.

Why is the air-bag or sound considered an article of value?

Because this organ in the cod or ling, when salted, forms nourishing and palatable food. But it is chiefly in the manufacture of isinglass, that the sounds of fishes are extensively employed. Sturgeon sounds are chiefly used for this purpose.

When in a sound state, the external skin of the air-bag (regarded as possessing strong muscular power) is supposed capable of contraction, so as to condense the air, and enable the animal to sink ; or of extension, so as to allow the air to expand, and aid the animal in rising in the water.

Why is isinglass so nutritious?

Because it consists almost entirely of gelatine.

Why is the air-bladder thought to be unconnected with the respiration of fishes?

Because this bladder does not exist in many fishes.

Why is the air-bladder believed to be subservient to the motion of fishes?

Because it is largest in such fishes as swim with considerable velocity.

Why have flat fish large lateral Jins?

Because they have no air-bladder to enable them to swim. In the shark the absence of the air-bladder is compensated by the size and strength of the tail.

Why does the lamprey creep slowly at the bottom of the water?

Because it has neither air-bladder nor fins to enable it to swim.

Why is the osteology of fishes but little attended to by naturalists?

Because the skeleton is more complicated than that of man, and is difficult to prepare and preserve. - Fleming.

The bones of fishes, when reduced to powder, are mixed up with farinaceous substances, and used instead of bread, by some of the northern nations.

Why do fishes leap?

Because of a violent effort of the caudal fin ; or, according to some, by bending the body strongly, and afterwards unbending it with an elastic spring.

Why are certain fish enabled to fly?

Because they have the air-bag of uncommonly large dimensions, wherefore the body has great buoyancy. The pectoral fins are likewise large, and having, by a leap raised themselves above the surface of the water, they continue in the air and move forwards, seldom farther than a hundred yards, by the action of these fins.

Why cannot these fish take long flights ?

Because the membrane of their fins soon becomes dry, when they again fall into the water. The flying fish generally leave the water to escape from other fish which prey upon them.

There is also a species of fish which is capable of climbing, and has been known to raise itself five feet above the surface of the water, and mount up the crevices of trees, by means of its various spines.