48 
to multiply in enormous numbers. In these rivulets, filled 
with water cresses and other aquatic plants, the little 
shrimps, which form so important a part of the food of 
the trout, are raised. Every day the daily rations allowed 
to the fish is gathered with nets in a few minutes; and 
it is a curious spectacle to see this food given to the 
fish. The young trout come from all directions in dense 
masses. They vigorously attack the little shrimps and 
do not allow asingle one to get to the bottom of the 
water. No matter how large the quantity of shrimps it 
vanishes in a few moments. 
The young fish of Messrs. Lugrin and du Roveray thrive 
admirably on this diet. Three basins, each having a sur- 
face of about 120 meters, contained about 70,000 fish of 
this year’s raising, grouped according to size, and all in 
excellent condition. From their well developed stomach 
and their finely rounded forms, it will be seen that these 
fish have not only never suffered hunger, but that they 
have always had abundant food of excellent quality. 
This kind of food, composed exclusively of insects and 
small crustaceans, is exceedingly suitable for these young 
fish on account of the large quantity of phosphate of lime 
which it contains; (1) and this circumstance explains the 
rapid growth, and the -exceptionally fine and vigorous 
condition of the young trout raised at Gremaz. 
It may be well to add that the profitable use made of 
the small shrimp streams will soon give way to a still 
simpler method of utilizing these small crustaceans, by 
proceeding in exactly the same manner with Daphnia, 
z.e., the fish will be successively, or rather alternately, 
passed from one basin to the other, to consume a stock 
<= ————— “= — 

(1.) It is well known that the substance which forms the skeleton of insects and 
crustaceans is, with many species, largely composed of calcareous matter, and is 
exceedingly rich in phosphate of lime. It is probable that to this circumstance 
must be attributed the result of Stoddard’s experiments: ‘‘ Three lots of young 
trout were placed under absolutely identical conditions ; one lot was fed on fish, 
the second on Annelida and mollusks, and the third exclusively on insects. Al 
the fish of the Jast-mentioned lot developed much quicker than those of the 
others.” In England insects are also considered excellent food for young trout. 
