FISHES. 



■489 



fish for propagating their kind ; and many of them bring forth 

 in the midst of winter. 



The same duplicity of character which marks their general 

 conformation, obtains also with regard to their manner of bring- 

 ing forth. Some bring forth their young alive ; and some bring 

 forth eggs, which are afterwards brought to maturity. In all, 

 however, the manner of gestation is nearly the same ; for upon 

 dissection, it is ever found, that the young, while in the body, 

 continue in the egg till a very little time before they are ex. 

 eluded : these eggs they may properly be said to hatch within 

 their body ; and as soon as their young quit the shell, they begin 

 to quit the womb also. Unlike to quadrupeds, or the cetaceous 

 tribes, that quit the egg state in a few days after their first con- 

 ception, and continue in the womb several months after, these 

 continue in the body of the female, in their egg state, for weeks 

 together ; and the eggs are found linked together by a membrane, 

 from which, when the foetus gets free, it continues but a very 

 short time till it delivers itself from its confinement in the 

 womb. The eggs themselves consist of a white and a yolk, 

 and have a substance instead of shell, that aptly may be com- 

 pared to softened horn. These, as I observed, are sometimes 

 hatched in the womb, as in the shark and ray kinds ; and they 

 are sometimes excluded, as in the sturgeon, before the animal 

 comes to its time of disengaging. Thus we see that there seems 

 very little difference between the viviparous and the oviparous 

 kinds, in this class of fishes : the one hatch their eggs in the 

 womb, and the young continue no long time there ; the others 

 exclude their eggs before hatching, and leave it to time and 

 accident to bring their young to maturity. 



Such are the peculiar marks of the cartilaginous class of fishes, 

 of which there are many kinds. To give a distinct description 

 of every fish is as little my intention, as perhaps it is the wish 

 of the reader ; but the peculiarities of each kind deserve notice, 

 and the most striking of these it would be unpardonable to omit. 



Cartilaginous fish may be divided first into those of the shark 

 kind, with a body growing less towards the tail, a rough skin, 

 with the mouth placed far beneath the end of the nose, five 

 apertures on the sides of the neck for breathing, and the uj)per 

 part of the tail longer then the lower. This class chiefly com- 

 prehends the Great White Shark, the Balance Fish, the Hound 



