47 
When, in the year 1442, | visited the Gremaz estab- 
lishment for the first time, I was positively astounded at 
the quantity of Daphnia in the basin, forming dense 
pte in the water, But that was the beginning of 
October, after a long period of fine and warm weather, 
during which these small crustaceans had had a chance 
to multiply at an enormous rate, 1 was, therefore, curious 
to return to the establishment to see how matters stood 
during the bad season, Vrom this point of view no 
better moment could have been selected for my visit, 
Without being exceptionally severe, the winter in this 
region has been somewhat prolonged, Shortly before 
my arrival the thermometor had fallen to 13 degrees 
below zero, On the day of my visit it was still 4 degrees 
below zero, and the basins, which had a feeble current 
of wate r, were covere dd with ice, The ice had been 
broken in several places, and we could, consequently, 
examine the water underneath, J must say that the 
Daphnia appeared to me to be just as numerous as during 
the fine season, which, however, is easily explained in 
water a8 cold as that in these basins; but when we dipped 
out some of the water from the bottom of the basing, 
with a sort of canvas pursenet, we brought up incredi- 
ble quantities of larva of the Chironoma and still more 
larve of the ephemera, The whole bottom of the basins 
seemed to be one mass of animal life, At every haul we 
got a big dish full of these larva, which are an exceed- 
ingly valuable article of food for the young fish, The 
water which is artificially prepared for the Daphnia is, 
therefore, likewise well suited for the developement of 
other small aquatic animals which can be utilized as food 
for young fish, . 
But Messrs, Lugrin and du Roveray are not contented 
with this source of food, Alongside of the basin there 
are small rivulets artificially made for raising small fresh. 
water shrimps (Gammarus pulex) which, by a method 
similar to the one employed for the Daphnia, are caused 
