260 THE ANIMAL KINGDOM. 



swimming bladder or " sound," they can rise and sink with 

 little effort. Many tribes of the human family, such as the 

 Esquimaux and Polynesians, almost live upon Fish, and even 

 in Great Britain, in fishing districts, it forms a great part of 

 the food of the inhabitants, and their capture gives employ- 

 ment to thousands. 



Fish inhabit all kinds of water, the sea, rivers, and ponds, 

 and many which live habitually in the sea come into rivers at 

 certain seasons ; and with respect to those which dwell always 

 in the sea, some inhabit certain tracts only, and confine them- 

 selves to them, just as quadrupeds do to certain localities on 

 the land. It has been a matter of wonder how the Fish get 

 into ponds formed by the drainage of lands ; but most ponds 

 are supplied by springs which run underground from adjacent 

 lakes or rivers, or by rills running on the surface, these 

 bring the ova or eggs, which in favourable situations become 

 hatched. Fish are exceedingly prolific, the eggs in the roe 

 of a Codfish were estimated by Lewenhoec, to be upwards of 

 9,000,000, but not one in a thousand comes to maturity ; 

 there are enemies on all sides to devour them before they 

 are hatched, and others to attack them afterwards. Some of 

 the rivers of France have lately been artificially stocked 

 with Fish by causing the fecundated spawn to be preserved 

 till they are of a bulk and strength to protect themselves. 

 This was effected by confining them in tanks floating in the 

 water and perforated with holes, and afterwards placing 

 them in a part of the river, inclosed both above and below 

 by means of nets, so as to keep away their enemies the 

 larger Fishes. 



Fishes were the first of the Vertebrated animals created, 

 and as a proof of the incorrectness of the doctrine of 

 development, these first-created Fish were of a class cor- 

 responding to the most highly organised Fishes of the 

 present day. 



Fishes are divided into tw r o families : 1, Osseous Fishes 

 (with a bony skeleton) ; 2, Cartilaginous Fishes (with a 

 cartilaginious skeleton). 



The Osseous Fishes are divided into six Orders : 



