200 Thirty- Second Annual Meeting 



General Bryant : Do the same conditions ever arise in fresh- 

 water ? 



Mr. Marsh : Yes, sir. If you have a mechanical plant like 

 the one here, and were pumping fresh water, there is no reason 

 why the fresh water would not become saturated in the same 

 way. 



General Bryant: Have you any instances of fish suffering 

 from this condition excej^t in salt water ? 



Mr. Marsh: I have no doubt that there are such instances, 

 yes, sir. 



Mr. Titcomb : I think this paper is especially valuable, and 

 possibly the fish culturists have not all appreciated it, regarding 

 the point I am going to bring out, and General Bryant's inquiry 

 would naturally bring it out. Here at this station the question 

 is easil}^ solved by having tight suction pipes, no leakage to ad- 

 mit air, but it appears that springs sometimes contain an excess 

 of air : Now, the fish culturist ordinarily in looking for a loca- 

 tion for a hatchery for an eyeing station will examine the spring 

 and will question whether the water contains sufficient air. It 

 seems that we have got to guard against superabundance of air 

 in the same wa3^ We have in the commission one station today 

 suffering from an excess of air coming right into the spring. The 

 air bubbles up and rise up through the spring to the surface of 

 the v/ater — that is the station at Erwin, Tennessee where Mr. 

 Jones is superintendent, and we have had serious trouble with 

 the fry before Mr. Marsh made some investigations and solved 

 the problem there as he has here. There we can probably arrange 

 matters so that the water will be all right in the hatchery by the 

 same treatment that we would give water which lacked air — • 

 aerate the water by passing it over a series of falls. Unfortun- 

 ately at this station the fall is not very great between the springs 

 and the hatchery. 



jMr. Xevin : In our hatchery between the spring pond and 

 hatching house there is a distance of twenty-five feet, and the fr .■ 

 in the troughs do not do so well as in the main hatching build- 

 ing, or main pond, and that is on account of the excess of air. 



Mr. Marsh : How does it get in ? 



Mr. Nevin : T don't know. 



