580 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [4'2] 



season of 18S4-'85 ; live fish are also sold, especially carp, ami also 

 trout, alter they have for two or three years furnished sexual products 

 for reproduction. Every year young salmon are placed in the Rhine 

 to the number of from 500,000 to 1,000,000, and in return the establish- 

 ment receives from the German Government a sum sufficient to cover 

 the annual deficiency, provided it does not exceed $5,950. 



The hatching apparatus used in the large halls of the Hiiniugen estab- 

 lishment are still substantially those invented by Coste, having frames 

 with a bottom of glass stems, although for these there have been sub- 

 stituted, to a large extent, other frames with a bottom of metal staves, 

 or a network of metal wire, used particularly when eggs of the finer 

 kinds of fish, such as Coregoni, are to be hatched. Generally the eggs 

 wdiich are to be hatched in the establishment are, when near being 

 hatched, placed in troughs made of pine-wood, about 3 meters long, 40 

 to 50 centimeters broad, and 15 to 20 centimeters deep [about 10 x 1£ 

 X £ feet], at the lower end of which there is a metal grating to prevent 

 the escape of the young fish. They are covered with a strong wooden 

 lid to prevent mice and rats from getting in, and to have the develop- 

 ment of the eggs carried on in darkness, which greatly favors such 

 development. These troughs are then placed in the open air, and after 

 the eggs have been hatched the young fish are fed until they are near 

 losing their umbilical sacs, when they are immediately placed in some 

 river or lake, it being considered better to place them in open waters a 

 few days before they have entirely lost the umbilical sac. When the 

 number of eggs to be hatched is very large, Mr. Haack also uses Cali- 

 fornia apparatus, more or less modified; especially those recently con- 

 structed by Professor Benecke on the principle of the La Vallette ap- 

 paratus. 



The young fish destined to be raised in the establishment are placed 

 in small basins laid in cement, into- which water runs continually. 

 Here they are raised and fed artificially, and are not taken out, except 

 in very cold winters, when for some days they are placed in basins in 

 the small wing on the right. There are also ponds for carp and for 

 some other cyprinoids (Tinea, Idus, &c), some small for winter, and 

 others large for summer; these ponds are used for reproduction and the 

 development of the young fish. The largest of these ponds covers an 

 area of 1 hectare [about 2£ acres]. The ground where it was excavated 

 w T as rented for the sum of $9.G5 per annum, and the annual income 

 from carp raising amounts to $289.50. 



After several experiments Mr. Haack has succeeded iu transporting 

 from Pisa to Hiiniugen live young eels, known by the name of "blind 

 eels." He keeps them for a certain time in cemented basins, and then 

 ships them to other parts, some as far as the most remote portion of the 

 province of Pomerania. 



The imperial establishment of Hiiniugen is the one which has given 

 the greatest impetus to the spread of the industry of fish-culture; but 



