46 
for the young fish, and since Messrs, Lugrin and du 
Roveray have demonstrated the great usefulness of the 
Daphnia in this respect, several pisciculturists have looked 
for some practical means of providing a sufficient quan- 
tity of these small crustaceans, Attempts to multiply 
them rapidly in ditehes filled with slightly muddy water 
suceceded; but this method presents serious inconveni- 
ences, According to Mr, Chabot-Iarlen, the Daphnia 
gathered in these ditches are extremely tender; the least 
agitation kills vast quantities; the greatest precautions 
are therefore required to gather them ; and, moreover, 
these small crustaceans impregnated with muddy water 
must be carefully washed in clear water, in order not to 
become actual poision for the young lish, 
The method employed in the Gremaz establishment is 
by far preferable. As [ have stated in my pre- 
vious report (Bulletin de la Societe d’Acclimatation, 
November, 1882), the Daphnia are raised in the very 
basins which are destined for the fish, When a basin 
has been sufheiently prepared for the development of these 
small crustaceans, they are allowed about a month’s time 
to increase ; then the fish are put in the basin, where they 
at onee find abundant and substantial food, Whilst 
this stock of food is being consumed, other provision is 
made, A neighboring basin is prepared like the first ; 
ae itis abundantly stocked with Daphnia, After another 
month has passed, the fish—-which by that time have 
consumed nearly all the food in the first’ basin—are put 
in the second, where they again find ample food. A 
month later they are again put in the first basin, which 
meanwhile has again become stocked with Daphnia, and 
so on, Phis method is extremely simple and convenient, 
Messrs, Lugrin and du Roveray, however, do not confine 
their efforts to raising Daphnia, but they likewise use larvee 
of insects, and especially small freshwater shrimps, which, 
as we shall see, form an exceedingly abundant article of 
food, particularly in winter, 
