63 
flow from the springs into the tanks and carry away 
the overflow. These rivulets, the bottoms of which 
have been impregnated by the Lugrin system, are filled 
with cresses and other water plants and produce the 
minute shrimps in such abundance that they are gath- 
ered daily in panfuls by a few sweeps of a gauze 
* scoop-net and fed to the fish in the swarming tanks. 
This part of the process is easily applicable to natural 
streams where a sufficiency of food does not already 
€Xxist. 
As to the applicability of this system to American 
pisciculture, there is apparently no room for doubt or 
question. The same natural conditions which exist at 
Gremaz can be found in nearly, if not quite, every 
State in the Union. The same food which is produced 
there may be used in growing nearly every species of 
fish which is artificially reared in the United States. 
American brook trout, the rainbow trout and Califor- 
nia salmon thrive admirably in the tanks at Gremaz. 
To conclude with the verdict of Prof. Francis Day, 
who, in October last, came specially from England to 
investigate and report upon the system which has been 
so successfully established there : 
“When I remark that a tank 35 meters (10 feet) 
long by 3 (10 inches) broad, and 4o centimeters (1 
foot 4 inches) deep, and capable of containing 20,000 
young trout can be fully stocked with food in fifteen 
days, so as to be able to sustain the residents for one 
month without any additional supply, I cannot help 
thinking that Mr. Lugrin has solved a difficult problem, 
and that his mode of cultivating the natural food of 
fishes will prove a great and lasting benefit to fishcultur- 
ists.” 
MarsEIL_LeEs, February 25, 1888. 
