FISHES. 381 



Among the oviparous fishes, hermaphroditism was long con- 

 sidered as a rare and accidental circumstance. Baster noticed 

 this occurrence in the Whiting, Duhamel in the Carp ; Haller 

 gave his testimony to facts of the same nature ; and Pallas be- 

 lieved that the genus Syngnathus had no males. Lastly, Sir 

 Everard Home, in the Philosophical Transactions for 1815, 

 states the same fact regarding the Lampern or Pride, and the 

 Gastrobranchus coccus of Blocli. 



The amazing reproductive powers of fishes are well-known. 

 In the ovary of the Cod in December were found 3,686,760 

 ova; in the Flounder in March, 1,357,400; in the Herring 

 in October, 36,960 ; and in the Tench 383,252.* And Blocli 

 relates, as the result of an experiment regarding the reproduc- 

 tive power of the Carp, that, in a pond of seven acres, in which 

 were placed four males and three females, ^the increase was 

 11 0,000 young carp, a number far too great for the size of the 

 pond, and the necessary supply of food. But this astonishing 

 capability of increase is modified by a thousand circumstances 

 which regulate the number produced to the supply of their food. 

 Myriads of these ova form the food of different species ; and 

 myriads more of the young may be supposed to be destroyed 

 in an element where almost all are destined to become the prey, 

 of one another. Notwithstanding these deductions, however, the 

 importance of this class as an object of commerce, and as a sup- 

 ply of food, hold out an inexhaustible field for the enterprize 

 of nations whose territories approach the sea. 



Of the migrations of fishes, and the causes which prompt 

 these annual influxes of certain fishes on certain coasts, little 

 is with certainty known. Probably they are regulated by the 

 same causes which influence the migrations of birds, to find 

 food and proper places for reproduction ; and the same instinc- 

 tive impulse which induces the salmon at certain seasons to as- 

 cend rivers, may bring myriads of fishes to the shores for a si- 

 milar purpose. 



Little is known with regard to the comparative age of fishes. 

 The carp has been known to reach 200 years, and the pike to 

 260 ; and if whales be found of less size now than in former 

 ages, when their fishery was but little attended to, it may be 

 conjectured, that their age is still more considerable. 



See a paper by Thomas Harmer in Phil. Trans. Vol. Ixvii. 280. 



