NOTES ON FISH-CULTURE IN GERMANY. 
319 
frequently rendered turbid by rainstorms, and with a depth of water varying from 
0.5 to 1 meter (1.6 to 3.28 feet). After the water has become turbid the young fish 
appear to be in particularly fine condition. Each box now contains 10,000 to 20,000 
young fish — the smaller number if brook trout, the larger if rainbow trout. It is 
customary in Sandfort to pour the tiny fish, immediately after they have been hatched, 
into these “nurseries” and to begin the feeding process, which with the rainbow trout 
is very easy, in these boxes. As the young fish grow the food is gradually changed 
to calf-liver without egg and then to beef-liver, which in June is fed to the fish just 
as it comes from the chopper. The feeding process has now become exceedingly easy 
and consists in simply throwing the food into the boxes with a common spoon. One 
person can easily serve six and later even ten boxes. 
In June the young fish are transferred to earth-ponds and sorted closely according 
to their size. Henceforth the losses will be very few. The use of “nurseries,” 
especially for young rainbow trout, has the advantage of great safety and cleanliness. 
The boxes are, after every campaign, covered with a coating of asphalt lac, and 
thus last for years. While the young fry are in the boxes, the eartli-ponds can be 
thoroughly cleaned and dried; and as they are filled again late in the season (in 
June) a limit is thus set to the development of larva and vermin. The cost of such a 
box, according to its more or less careful finish, varies from 50 to 70 marks ($11.00 to 
$16.00), which can hardly be considered too much, in view of the comparatively high 
value of the yearlings produced. 
Of fourteen boxes which in 1893 were used in the Sandfort establishment, those 
containing rainbow trout yielded the best results. One box, which had been stocked 
with young fry from 20,000 eggs, produced in June over 17,000 young fish. It is 
possible to keep the young fish in the boxes till November, in smaller numbers (up to 
5,000); but, from June on, the growth in the earth ponds is much more satisfactory 
than in the boxes, especially as in ponds filled late in the season young fish find an 
ample supply of natural food, such as Cyclops and other small crustaceans, and later 
the small pond-snails. 
The only objection which could be raised against this system, which is apparently 
based entirely on artificial food, is that such fish would not be able to get their food 
in a brook or open pond. But apart from the fact that the instinct for seeking food 
and for self-preservation is exceedingly strong in all animals, the well-fed young fish 
from the fish-cultural establishment will surely carry with him a greater reserve of 
food than the hungry wild fish, and would be more apt to push the latter away from 
the food than perish. Fish can (and this is hardly sufficiently known) live a long time 
without any food whatever, and even lose 50 per cent of their weight without perish- 
ing or losing the faculty of seeking food. To see how fish which have just been fed 
will go gnat-hunting, it will be sufficient to watch yearling ponds, like those at Sand- 
fort, some afternoon or evening. The eye can not quickly enough count the fish which 
leap out of water for gnats. If this is not sufficient proof all that will be necessary 
will be occasionally to dissect an artificially raised fish, and see what its little stomach 
contains, in addition to the artificial food, in the shape of snails, gnats, and small 
crustaceans. 
