400 



Inland Water Culture 



3. More knowledge 

 is needed of the water 

 bodies themselves; 

 knowledge of their 

 physical, chemical and 

 hydrographic c o n d i - 

 tions, their purity, con- 

 tamination, and all 

 other conditions that 

 affect the welfare, that 

 promote or hinder the 

 normal growth and ac- 

 tivities of the useful 

 organisms contained in 

 them. We must know T 

 these things in order 

 to know how to make 

 and keep the waters productive. 



Knowledge is being accumulated in all these lines 

 in a slow and desultory way, thro the voluntary 

 activity of many diverse and widely scattered agencies. 

 Fish culture has not yet had the benefit of that 

 efficient agency of economic progress that has brought 

 such rapid improvement in animal husbandry — the 

 experiment station. A fish cultural experiment station 

 is what is now urgently needed : an institution equipped 

 for water culture, and charged with the duty of carrying 

 out a well planned line of experiments bearing on its 

 economic problems. This is needed to supplement the 

 hatcheries and to bring their work to fruition. 



Fig. 239. Eggs of the pike, Esox 

 lucius, overgrown with two species of 

 fungus. 



