[3] FAILURES AND SUCCESSES OF FiSH-CULTURE. 439 



RUSSIA. 



Professor Malingreu takes occasion to remiud the reatler that for 

 more than twenty years Finland possessed sahnon-hatching- establish- 

 iiiems, which owed their existence to the imx)etns given by Franca 

 throngh its establishment at Huningen. The superintendence of sal- 

 mouculture in Finland was principally in the hands of Professor Ilohn- 

 berg, of Ilelsingfors, who had studied artificial fish-culture in Norway. 

 During the period of 1858 to 1804 salmon hat(;heries were established 

 on the Kymniene River, on the Wucksen (near Kexholm), on the Ulea, 

 Tornea, and Urpala, which, however, were as little successful as some 

 other establishments devoted to the hatching of brook trout and lake 

 trout. Some of these hatcheries produced 100,000 young salmon jier 

 annum ; Kexholm even as many as 200,000, Avithout, however, causing 

 any noticeable increase in the number of lish. Professor Malmgren 

 siraplj- mentions this fact, without telling us anything regarding the 

 causes of the failure. I am inclined to think that probably one of the 

 l)rincipai causes, as in many of the Swedish and Norwegian fish-cul- 

 tural establishments, must be found in the use of Avarm sjjring water, 

 which is more or less lacking in air. In countries of the latitude of 

 Sweden and Norway spring water is used for artificial fish-culture, if 

 possible near the source, because many of the waters freeze entirely 

 during the severe winter. On account of its greater degree of warmth 

 spring water is not so liable to freeze, but it is apt to develoj) the eggs 

 and young fish prematurely, so that the latter have consumed the um- 

 bilical sac and are ready to be placed in open waters at a time of the 

 year when everything is still covered with snow and ice. If these 

 tender young fish are placed in open waters at this season they must 

 perish, partly on account of their not being able to resist the severe 

 weather, and partly owing to the fact that at this season of the year 

 those insects on which they principally feed have not yet made their 

 appearance. If these young fish were, at this season, placed in ponds 

 and ditches, in order to raise them there, the fact that these waters 

 would be more or less covered with a sheet of ice would be prejudicial 

 to their growth. Under these circumstances it is not surprising that 

 the young fish are decimated ; and if, on the other liand, the fish-cult- 

 urist wishes to keep the prematurely developed young fish in the hatch- 

 ing tanks till si)ring, he is obliged to supply artificial food, which, espe- 

 cially if the number of fish is large, will have its peculiar difficulties. 

 At the same time the fish growing from week to week in the warm 

 spring water, which more or less lacks oxygen, will not get the quan- 

 tity of fresh air necessary for their development, and consequently 

 large numbers of them will die. As fish-culturists in Sweden and Nor- 

 way, where Professor Ilolmberg studied fish-cull ure, work with spring 

 water, it is i)r()bable (although Piofessor Malmgren does not say any- 

 thing about it) that this has also been the case in Finland. This sup- 



