THE RELATIONS OF FISH TO MAN 295 



develop. They are distributed either as well-developed eggs 

 or as young fish, and are planted in the waters from which the 

 adult fishes were taken, and also in waters where the fishes are 

 not native. 



In 1909 the Bureau of Fisheries operated 35 hatcheries and 

 84 subhatcheries, auxiliaries, and egg- collecting stations ; these 

 were located in 32 states and territories. The regular hatcheries 

 may be classified as follows with reference to the fishes propa- 

 gated : marine species, 3 ; river fishes of the eastern seaboard, 5 ; 

 fishes of the Pacific coast, 5 ; fishes of the Great Lakes, 7 ; fishes 

 of the interior regions, 15. The total output of fish and eggs in 

 1909 was 3,107,131,911. During the year applications were 

 received for fish for planting in 10,111 different bodies of water. 

 A summary of distributions is given in the table on page 294. 



Besides this, 568,150 eggs were shipped to Argentina, France, 

 and Germany. 



The Artificial Propagation of the Lake Trout. The methods 

 employed in artificially propagating fish may be illustrated by an 

 account of the lake trout. Adult lake trout are captured chiefly 

 during the spawning season in September, October, and Novem- 

 ber in gill nets, pound nets, or by hook and line. Government 

 employees called spawn takers accompany the fishermen on 

 their trips to collect the eggs of the fish captured or else the 

 fishermen themselves are forced to collect the eggs for the 

 government. The ripe females are selected and their eggs 

 squeezed out by the spawn takers, a process known as stripping. 

 The eggs are allowed to fall into a milk pan. They are then 

 fertilized by squeezing some of the milt (spermatozoa) from a ripe 

 male into the pan and stirring up the eggs with the tail of the 

 fish. When the pan is half full, the eggs are washed and trans- 

 ferred to a five-gallon pail. Each pail holds about 75,000 eggs. 



The eggs thus obtained may be kept at field stations for several 

 days or shipped directly to the hatchery. In either case they are 

 placed on shallow trays, each holding 10,000 eggs, and eighteen 

 of these trays are placed in a box with moss packed around them. 



