NOTES ON FISH-CULTURE IN GERMANY. 
313 
vegetation and which successfully answer the purpose of supplying the water with 
oxygen and live animalcula. For raising these aniraalcula I would not recommend 
ditches with standing water and liquid manure. It is true that these ditches develop 
a vast quantity of suitable live food, but they also produce water-beetles and other 
injurious animals. 
The difficult question as to the proper quantity of fry to be placed in a pond can be 
satisfactorily answered to suit each individual case only. At Sandfort 4,000 young 
fish are placed in autumn in a raising-pond with an area of 180 square meters (1,937.5 
square feet) aud a depth of 1.5 meters (4.9 feet), and as the principal object is to 
produce as fast as possible a fish weighing not more than one-fourth pound (the 
favorite weight), all small and weakly as well as all fry of excessive size are eliminated, 
and the normal fish measuring 8 to 11 centimeters (3.1 to 4.3 inches) are used for 
raising. Where artificial food is used, artificially raised and fed fry are the best, as 
fry from natural ponds are as a general rule not so even in size and are not evenly fed. 
I am also of the opinion that they are more inclined to cannibalism than domesticated 
fish. 
The great advantage which a fish-cultural establishment possesses over the 
culture of natural ponds, is in its ability to place its products on the market or retain 
them, just as it suits the proprietor. The natural pond puts its products on the' 
market at the wrong time, either in autumn when the season for selling trout has not 
yet commenced in the great fish market, or in spring after Lent is over. No wonder 
that under these circumstances fish-dealers guard their interests by making only 
cheap offers. But fish-dealers also know where they can get fish at a season when 
ice covers the natural ponds, without running any risk from short weight, losses from 
death, and other causes. With some little care, a fish-cultural establishment can 
manage to have its fish ready for sale at the proper time and when they will fetch the 
highest price. 
Even if the young fish in course of raising are most carefully sorted, some will be 
retarded in their growth, while others will grow more rapidly than the rest. Those 
whose growth has been retarded (probably 10 to 15 per cent) should be placed in a 
reserve pond and fed there; customers for them will be found in the spring. Most 
fish, however, will have their full weight from October to December, and the regular 
rotation of a raising-pond can be completed within one year. Those fish which have 
grown more rapidly than the rest will, in a well-regulated fish-cultural establishment, 
serve for selectiug breeders for future campaigns ; and if there are larger ponds it will 
pay (as far as rainbow trout are concerned) to keep these fish for two years longer. 
In stock raising-ponds it is, above everything else, necessary to have normally 
developed and evenly sorted fish ; and these are best obtained in autumn from the 
yearling ponds, immediately after the close of the fisheries. The fish are then in 
prime condition, and, owiug to the cooler weather, transportation is cheaper than in 
spring. In the raising-ponds the fish will eat and grow all winter through, and a 
10- centimeter (3.9 inches) fish obtained in autumn will naturally turn out better than 
such a fish obtained in spring. 
As a general rule, it is very difficult to accustom the German brook trout to 
artificial food. It is a shy fish, and must be deprived of every hiding-place, aud 
placed in pretty close confinement to induce it to eat artificial food. But its Scotch 
cousin, the u Loch Leven,” through domestication continued for several generations, 
