Ward. — An Experimental Fish Plant 175 



struction the territory was without any permanent water 

 bodies. It is important to consider the bearing of this 

 upon the experiment under consideration. A fish pond 

 is being built where, within the knowledge of man, no 

 pond has ever existed before. A unit for existence of 

 water life is being constructed in a county where such 

 units have not existed under natural conditions. In a 

 region where temporary pools of water have heretofore 

 furnished only possibilities for aquatic existence, we are 

 constructing a permanent aquatic unit, and planning to 

 test in it the conditions of existence for various organ- 

 isms, especially the fish. 



Because of the fact that no large supply of flowing 

 water is available, and what we use will come from tanks, 

 cisterns, or wells, we are compelled to use it continuously ; 

 and a plant will be installed to circulate the water. The 

 general plan in mind is to take the water from the outlet 

 box by means of a small pumping apparatus, and turn it 

 back again through the inlet. This inlet pipe will be 

 raised above the surface of the water, so that the water 

 inflow will be aerated in coming out and falling into the 

 pond, again. Starting absolutely from the beginning, it 

 will be possible to keep a record of the time at which each 

 addition is made to the pond, and of all the material, 

 either plant or animal, of perceptible size that goes into 

 it. Of course, it will be impossible to control the wind 

 and dust, and all of you are aware that the microscopic 

 life of the water is probably carried in the form of spores 

 or resting stages in the dust. No doubt many things will 

 be brought into this pond that will surprise the recorder, 

 and it is possible that in this way some information may 

 be gained regarding the stocking and restocking of water 

 bodies with the minute plant and animal life. It will also 

 be impracticable to control the insect life, but apart from 

 these, we shall be able to determine the origin of any ele- 

 ment and to know that all increase or decrease is depend- 

 ent on conditions which we fix. In other words, in a 

 new and definitely circumscribed environment the condi- 

 tions will be under control so far as possible, and all of 



