508 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



1. Through' the box, with compartments at a certain distance from 

 each other, and at a convenient height above the boxes, zinc pipes are 

 placed, pferced by straight openings, joined to each other, and at their 

 ends to other larger pipes. Some of the water coming from the filters 

 in this way flows out into the box, through the openings of the pipes, 

 in the shape of a fine rain. All these small drops of water j)ass through 

 the air during their fall and become saturated with oxygen ; in striking 

 the surface of the water, they refresh it with diminutive drops, which, 

 rising and falling, increase the absorption of oxygen. 



2. To renew in the water the oxygen destroyed by the respiration of 

 the fish, air is also blown into it by means of bellows. This method is 

 particularly useful, because the air, entering the water from above and 

 below, only passes through it slowly, being retarded in its progress by 

 the pressure of the upper layers. Moreover, the contact between the 

 water and the air is more complete, and is brought about on compara- 

 tively larger surfaces, which, of course, causes a greater absorption of 

 oxygen. Ju following this method, care should be taken to blow air 

 into the water for a tolerably long time; and if it is impossible to do it 

 continually, it should at least be done in such a manner as to let this 

 aerating process go on, not only in one place of the box, but throughout 

 its whole extent. 



3. As, independent of the respiration of the young fish, the decrease 

 of oxygen is brought about by heightening the temperature, this incon- 

 venience is remedied by putting ice in the filters or in the boxes, the ice 

 being put in special receptacles, so that it cannot communicate its 

 impurities to the water. 



Jointly with this method, the following is also employed : as soon as 

 the temperature of the water commences to rise, the embryo, even if it 

 should not yet have reached the state of young fish, is transferred to the 

 ponds, where, as much as possible, it is placed in the bed of the Pestooka 

 Eiver, which flows through all these ponds. 



The extent of the establishment enables it to fecundate annually 

 5,000,000 lavaret* eggs, 2,000,000 trout eggs, and more than 1,000,000 

 salmon eggs. The basins and nurseries are large enough to raise and 

 feed every year more than 600,000 fish. Besides this, the establishment 

 can prepare for the trade about 1,000,000 eggs which have reached that 

 stage of their development when the eyes of the embryo can be dis- 

 cerned through the skin. 



The establishment of Nikolsky, for the foundation of which, inde^ 

 pendent of the personal funds of the founder, the government has 

 granted a subsidy of 30,000 rubles, ($21,000 gold,) was, till the year 

 1868, under the dii-ection of a society of pisciculturists, but since that 

 year it has become the property of the national treasury, and is at 

 present under the department of agriculture and rural industry. As 

 long as it was in the hands of private individuals, its aim was almost 



* White-fish, (Coregonus.) 



