560 



REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



[22] 



to whom they are sent, and generally some directions for their treatment 

 by the railroad employes. 



In Germany packages of eggs are received in the mails as postal par- 

 cels, and the administration of posts is directed to treat the package with 

 the greatest care, in compliance with the request " urgent" written on 

 a piece of red card-board attached to the usual label. 



Tanks and ponds for salmonoids. — My report would not be complete 

 as regards salmon culture if I did not mention the open tanks ami ponds 

 which in many establishments are used for keeping the stock of sal- 

 mouoids. 



The tanks are laid in cement, and covered with an iron grating, and 

 the salmonoids are kept in them, separated according to age. They are 

 so arranged that the fish in them can easily be fed artificially. As re- 

 gards the matter of artificial feeding, tanks are perhaps better than 

 ponds, as a possible excess of food* can more easily be removed in the 

 former, and as it is also easier to prevent any injurious pollution of the 

 water. 



Special mention should be made of a simple contrivance adopted at 

 Hiiuingeii to protect the fish kept in certain provisional tanks, with 

 wooden sides, especially against rats, which, if they have once got into 

 them, find no way to get out. For this purpose boards are placed atright 

 angles with the vertical sides of the tank, and projecting a little over 

 the water, flow this contrivance may serve as a trap will be under- 

 stood without any further explanation by a glance at Fig. 7. 



Jig. 7 



Trout which have reached a certain age are generally placed in ponds, 

 in company with other non-carnivorous fish, which rid the water from 

 any superfluous vegetation (especially alga 1 ), and thus enable the sal- 



* Daily visits are made to the hatehiug-box to remove the spoiled eggs. Among 

 the substances employed to feed salmonoids I have observed meat ground fine, meat 

 flour, dissolved brain, heart chopped line, cut-up entrails, and larva' of Hies bred in 

 decaying flesh. There are many more or less complicated machines for grinding the 

 food, but as they have been described in various treatises, I need not give any further 

 description of any of them, not even of the ingenious hydraulic grater for meat 

 which I saw at Seewiese, because its construction can easily be imagined. 



