FECUNDITY OF FISH. ll'» 



able length. Everywhere they encounter voracious 

 enemies. Pursued into tlie pools, tracked in the 

 sands, these creatures escape annihilation only by 

 their extreme fecundity. 



It would seem as if Nature — in the greater 

 number of beings that people the ocean — had 

 sought to compensate them by an incredible fe- 

 cundity for the causes of destruction by which they 

 are surrounded. Some fish of large size have only 

 two or three young, like the majority of terrestrial 

 animals ; but what shall we say of the fertility of 

 the herring, the mackerel, the cod, the sturgeon, and 

 other inhabitants of the seas? It has been calcu- 

 lated that if a herring could multi{)ly during twenty 

 years without losing any of its spawn or fry, its 

 offspring would form a mass ten times greater than 

 the globe. Obviously, the smaller creatures which 

 are destined to serve as food to these enormous 

 hosts must be more prolific still ! 



As we advance towards the equator, vegetation 

 becomes less abundant and less varied. The waters 

 are too much heated to be agreeable to the greater 

 number of the algae, and if in any part of the 

 equatorial seas the submarine vegetation attains the 

 scale of grandeur, it is still wanting in the delicacy 

 and elen^ance which characterise the vegetation of 

 the temperate zones. 



