American I'islicrics Society. 171 



Mr. Lane : I don't know Init it wonld ; I iliink its bcinpf 

 ground so very fine will produce a more rapid urowlli than it 

 would to take the liver raw. 



Mr. Thompson : Rci^arding" the food, 1 would like to state 

 that it is to be considered accoriling to tlie point of view in 

 which you look at it. The commercial hatcheries take a very 

 different point of view from the Commissions ; they wish to grow 

 a fish that has a very delicate flavor, and on that account they 

 necessarily must get some food that will produce it, and of course 

 we know that with fish as with anything else, there is a change 

 of flavor according to the kind of food consumed. One variety 

 of food alone I think is not the best, a change is beneficial. But 

 in otir work we are not interested in the flavor at all, we are 

 not producing fish to turn on the market, but to plant in public 

 waters where the natural food does the rest, and gives' them 

 that peculiar flavor that has created such an a])petite for trout. 

 So. on that account, we have no interest in getting a food with 

 a flavor, and I think in that way our standpoint is a little dif- 

 ferent. 



Then in regard to this green slime that is found in ponds, I 

 wish to say that the Iowa station had some experience with it. 

 In one pond, I remember, there was a sand}' and gravel bottom, 

 no loam and scarcely any vegetation, on this sandy bottom the 

 vegetation did not take hold rapidly. Other ponds there have a 

 loam and mud bottom where there is more or less vegetation 

 which took hold and spread rapidly — and this slime also repro- 

 duced itself very rapidly. The fish that were placed in the ]).Hid 

 first mentioned and spawned on the sandy bottom did not do 

 very well. The bottom attracted the sun, there was scarcely any 

 protection, and, as the spawning operations were visible, they were 

 interrupted in them by other fish coming around and eating the 

 spawn after it was extruded ; the few fish hatched there found no 

 food, and there were comparatively no results from that pond ; but 

 the other ponds that I speak of. where the bottom was covered 

 with this vegetable growth and slime, produced good results — the 

 fish there did well. Thev would select their spawn.ing place 



