200 ZOOLOGY. 
millions of young herrings, hardly one comes to maturity, owing to the 
ravages made among their number by the rapacious fish and other animals, 
man not excepted. Yet although they form the food of myriads of fishes, 
of hundreds and thousands of men, the supply is always equal to the 
demand, and no perceptible decrease in number can be observed. Similar 
instances might be furnished by the cod, the shad, the mackerel, &c. 
Of all oviparous animals, fish are perhaps the most prolific. Among these 
the cod-fish (Morrhua) is pre-eminently conspicuous. A single female has 
been calculated to produce as many as 9,000,000 eggs in a single season. 
There is no intercourse of sexes, excepting among a few of the Plagiostomes, 
the eggs being fertilized by the male after their evacuation by the female. 
Some species are ovo-viviparous, the eggs being hatched in the abdomen, or 
else in especially contrived pouches, as in Syngnathus. A slight approach 
to a placental connexion of mother and embryo, is made in some of the 
sharks. The eggs are deposited in various places, on sticks, stones, grass, 
in furrows of the sand, &c.; in rare cases a nest is built, consisting either 
of a single pile of stones, as in some of the North American Cyprinide, or 
else a more complicated structure of grass and sticks is built, as in the 
Callichthys of Demerara, and in various species of Gasterosteus. It is a 
little singular, that it is generally the male who takes upon himself the care 
of the eggs and the construction of the nest. | 
It is difficult to speak with any certainty as to the longevity of fishes, as 
few are permitted to reach their natural term of years. Some species, as 
Pike and Carp, kept in fish ponds, have, however, been known to live to a 
great age. Thus Buffon speaks of carp, in the moat of the Comte de 
Maurepas, 150 years old. Gesner refers to a pike having been caught in 
Suabia, in 1497, bearing an inscription purporting to have been appended in 
1230, the age thus being (at least) 267 years. The animal was said to 
weigh 350lbs., and to have a length of nineteen feet. 
The flesh of most fishes is edible, although that of some is difficult of 
digestion. They are rarely, or never, poisonous in themselves ; a property 
only acquired by consuming poisonous plants or animals. Fresh-water 
fishes are more generally edible than marine, although, as a class, not so 
savory. Other parts of the fish are of economical value besides the flesh. 
The oil of some is very valuable ; the air-bladder of the sturgeon furnishes 
the isinglass of commerce; the roes of the sturgeon, pike, carp, &c., fur- 
nish caviar. The shagreen skin of some Placoids is used for polishing, and 
for making ornamental coverings. The bones are used for fish-hooks, and 
other purposes. The Gymnotus or electric eel, the Torpedo, and the Silurus 
electricus, are capable of giving powerful electric shocks. 
CLASSIFICATION OF Fisu ES. 
The first scientific classification of fishes is that of Artedi (1738), who 
distinguishes them into cartilaginous (Chondropterygit) and bony; these 
being subdivided into fishes with bony branchiz and soft fin rays (Mala- 
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