176 American Fisheries Society 



those under control will be definitely measured and re- 

 corded. 



Evidently the possibilities of experimentation are pres- 

 ent here as they could not be in a larger plant. They are 

 also to be attacked in a very different fashion. In one 

 sense, they are not at all the problems that concern the 

 practical fish culturist, who receives from state or na- 

 tional authorities a definite sum of money and is expected 

 to show the hatching and planting of a commensurate 

 number of young fish. The primary object of this plan 

 will be experimentation and that will be carried out on 

 a purely biological basis. Studies will be made on all the 

 various types of organisms with a view to determining 

 the most favorable conditions of existence. That means 

 as regards the fish the effort will be made to ascertain 

 what factors modify the number of fish, the rate of 

 growth, the rapidity and perfection with which they reach 

 the adult condition, how different kinds of food affect 

 them, how differences in the environment of temperature, 

 chemical constitution, and vegetation, as well as other 

 living things which are in the water, but do not constitute 

 a part of the food, will influence their welfare. In this 

 field, we are very fortunate at the University of Illinois 

 in having as a member of the staff Dr. V. E. Shelf ord, 

 whose valuable contributions to the study of the funda- 

 mental conditions of aquatic existence are very well 

 known. It is hoped that taking advantage of these im- 

 portant researches, it may be possible to determine their 

 relations in a practical way to the problems of the fish 

 culturist. 



The general arrangement of the plant favors the easy 

 transfer of the fish at any time from the pond to the 

 aquaria within the greenhouse or the laboratory of the 

 vivarium, where they can be kept under a much more 

 limited environment and examined more closely and con- 

 stantly, as well as subjected to artificial influences and 

 the experimental environment of the laboratory. The 

 small size of the plant and the ease with which one of 

 the little ponds can be run off makes it possible to alter 

 the environment rather quickly, by changing the water, 



