350 



THE AMERICAN NATURALIST 



[Vol. LII 



scientists may render real service along the general lines 

 indicated in this paper. To be more specific, they may be 

 summarized as follows: 



(a) To determine the life history and food habits of the small fish and in- 

 vertebrates present. 



source of food for all animals, 

 (o) To determine if more plants can be made to grow in water naturally 



lacking sufficient plant life. 

 (d) To determine if it is possible to introduce enough natural food for 



fry and fingerlings to keep them from starving, as many of them 



probably do now in such ponds as many of those in the Adiron- 



When these problems are solved, the next step in effi- 

 ciency in fish culture can be taken. It will require the 

 cooperation of many scientists. The result will be the 

 substitution of an intelligent method of restocking in 

 place of the present one, which is often unintelligent or 

 politically influenced. 



(a) It is necessary to know the complete life history of such parasites as 

 the Trematodes before any one can formulate preventive meas- 

 ures. There are at present at least four different species of Tre- 

 matodes found in our fresh-water fish and the complicated life his- 



(6) The causes leading up to the usual epidemics in fish must be deter- 

 mined before these can be prevented. This is a problem for the 

 bacteriologist and the protozoologist- 



When these problems are worked out, an enormous 

 amount of fish food will be conserved for human needs. 



ure will be found 



