BULLETIN OF THE UNITED STATES FISH COMMISSION. 257 



they can be made to come to the surface as soon as they see the hand 

 stretched out over the water. This spectacle, however, is soon followed 

 by another pitiable one. The sticklebacks, confined within the narrow 

 limits of the glass, do not find food enough, and begin to attack each 

 other, and soon a desperate civil war is waging in the glass. The 

 stronger pursue the weaker, and although they are not able to swallow 

 them entire, they nevertheless inflict terrible wounds on them. Soon 

 some of the fish may be observed which are hindered in their move- 

 ments, because their tail has been bitten off either entirely or in part. 

 The wound soon grows worse, and the poor little animal pines away 

 and dies ; but even in its death agonies it is assailed by its cruel ene- 

 mies. The fish continue this war until only two are left, which retire 

 each to a different corner of the glass. Here they sit and watch each 

 other with eyes full of hatred and envy ; and if one of them is bold 

 enough to enter the domain of his adversary the result is a mortal 

 combat. 



If this is the way the little sticklebacks act, what can we expect from 

 the greedy pike, the scourge of the fresh water, or the dangerous shark, 

 which reaches the size of the large dolphins and is continually roaming 

 about the sea, devouring everything that comes in its way ? Woe to 

 the unfortunate sailor who falls overboard in waters where there are 

 sharks. 



If we consider that nearly all fish are carnivorous and live by robbing 

 and murdering, we must confess that the population of the sea must be 

 infinitely larger than that of the land, for otherwise fish would not find 

 food enough. 



III. — A QUERY AND ITS ANSWER; FURTHER OBSERVATIONS. 



After the foregoing the reader will perhaps be tempted to say : " If 

 that is the way things are carried on in the water, I am inclined to be- 

 lieve that life in the water must eventually die out. How can any race 

 of animals exist when such a continuous slaughter is going on ? How is 

 it that the larger of these insatiable animals have not long ago entirely 

 destroyed the smaller ones, finally to die themselves of starvation, 

 leaving nothing but their skeletons floating in the waters of the ocean 

 which has by that time become a howling wilderness ? " Those animals 

 which are intended to serve as a prey to others have greater fecundity ; 

 they produce more young ones than those animals which live on them ; 

 the carnivorous animals are therefore never in want of food, which con- 

 sists of weaker animals, and still the races of the latter do not die out. 



It will readily be seen how life in the water does not become extinct, 

 in spite of all the scenes of murder which are there enacted, if we re- 

 member that, as a general rule, the water animals increase much more 

 than the land animals. There are animals which are destroyed in in- 

 numerable quantities, both by their natural enemies and by man. Such 

 are the herring and the codfish, whose number does not seem to have 

 Bull. U. S. F. 0., 82 17 March 91, 1883. 



