THE HISTORY OF FISH-CULTURE. 495 



especially iu the sliallbw lakes, whicli are well known for their wealth of 

 fish, the third conditiou of rational pisciculture mentioned above would 

 often have been disregarded, L e., people would have fished the young 

 fish before the age of maturity if nets with narrow meshes had not been 

 prohibited. 



2, — PISdCULTURE. 



The decrease of fish in consequence of a bad and destructive system 

 has attracted the attention of the governments, nearly all of whoiu 

 devote more or less considerable sums to the encouragement and devel- 

 opment of the fisheries, in order to diminish the destruction of fish by 

 means of various i^rotective measures. The decrease of the Russian 

 fisheries has led the imperial ministry of domains to make a series of 

 statistical researches with regard to the fisheries, with a view of throw- 

 ing light on all the causes of this decrease. These researches, com- 

 menced in 1859 and finished iu 1872, have been made iu the Baltic, the 

 Polar Sea, the White Sea, the Caspian. Sea, the Black Sea, and the Sea 

 of Azov, as well as in the more important lakes. The result of these 

 investigations has served as a basis for the new legislation, and has led 

 to administrative measures looking toward the itroteetion and develop- 

 ment of the fisheries. 



In Paissia, as well as in other countries, the government has been 

 aided in its efforts by a new science, which in our days has become 

 of the greatest importance as a branch of national industry. The 

 labors of various distinguished scientists, who have devoted them- 

 selves to the study of icthyology, have led to interesting discov- 

 eries, several of which have proved of the greatest practical use. One 

 of the most important among these last- mentioned discoveries is the 

 artificial impregnation of spawn, which, as experience has shown, 

 enables us to multiply the most valuable species iu the most favorable 

 localities; or to renew the wealth of fish which had been exhausted by 

 a destructive system of fishing. 



This discovery can be traced back to the middle of the eighteenth 

 century, but its practical application as a branch of industry dates only 

 thirty years back. The artificial raising of fish is in our days encour- 

 aged and aided by government, has developed extensively, and has 

 rendered the most valuable services to the public well-being. 



Pisciculture, or the art of propagating fish, was known to all civilized 

 nations even in the most remote times. In the beginning, the following 

 method was observed : At the spawning-season, fagots and branches 

 . were placed in the rivers and their tributaries, forming hedges, on which 

 the fish deposited their roe as on a natural bottom. After the roe had 

 been impregnated, it was gathered and taken to those places where one 

 wanted to introduce fish or multiply them. 



In the fifteenth century other methods of propagating fish were 

 employed. Long wooden boxes were prepared, open at the top, and their 

 straightest sides being composed of osier or reed trellis ; at the bottom of 



