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 (Mo7'r/iua) 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 Plaginstomes, 

 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 Syngnatlms. 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 CyprinidcB, or 

 else a more complicated structure of grass and sticks is built, as in the 

 Calliclilhys 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 Buflibn 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 Fishes. 



The first scientific classification of fishes is that of Artedi (1738), who 

 distinguishes them into cartilaginous {Chondropterygii) and bony; these 

 being subdivided into fishes with bony branchiae and soft fin rays {Mala- 

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