ARTIFICIAL PROPAGATION OF WHITEFISH, ETC. 23 



nets, or where exceptionally large catches are being made, two spawn 

 takers may be detailed to one boat. 



Pans, pails, and dippers are taken on board and made ready by 

 the time the nets are reached. As the net is lifted the men disen- 

 tangle the trout and throw them on deck, where the spawn takers 

 sort them over, taking the eggs from ripe females and impregnating 

 them with milt from the males. During very severe weather the fish 

 are thrown into the hold instead of on deck, and the work is done 

 there. 



On the small gasoline boats operated by two to four men the crew 

 takes the eggs and delivers them to the bureau's agent or to the col- 

 lecting boat. The eggs are sometimes taken at widely separated 

 points and shipped to the main field station and then to the hatchery. 



The manner of taking the eggs is similar to that employed in tak- 

 ing spawn from other trout and salmon. First, a female is taken up 

 and the eggs, if mature, are gently stripped into an ordinary milk 

 pan and then impregnated with milt from a male. This operation is 

 repeated until the pan is half full, when the eggs are " washed up " 

 and poured into a 5-gallon pail. The washing-up process is per- 

 formed by filling the pans with water and allowing it to run off, 

 repeating the act until the water poured off no longer appears milky. 

 As the specific gravity of the eggs prevents their rising to the sur- 

 face, this can be done without loss if ordinary care is exercised. The 

 pans are refilled and emptied in this manner until the pail is half 

 or three-fourths full, when it will contain about 75,000 eggs. Other 

 pails or buckets are brought into use as often as may be necessary. 

 To keep the eggs from dying, the water is changed in the large pails 

 every hour until the eggs are taken from the boat and transferred 

 to scrim trays or floating boxes. All pans, pails, and other metallic 

 utensils are coated with asphaltum paint to prevent the appearance 

 of rust, which is fatal to the eggs. 



"Wlien the weather is so cold that there is any chance of the eggs 

 freezing to the pan, two pans are used. The outside one is partly 

 filled with water, upon which floats the pan that is to receive the 

 eggs as they are stripped. The pan of water protects that part of 

 the inside pan where the eggs rest, and in that way their temperature 

 is kept above the freezing point. 



SHIPPING EGGS TO THE HATCHERY. 



When spawn takers are operating at a distance, the eggs are held 

 at conveniently located field stations, whence they are sent to the 

 hatchery as soon as possible; but if the stations are at isolated 

 points on the lakes it is often necessary to hold the eggs for several 

 days before means of transportation can be obtained. In such cases 

 the eggs are held in floating boxes, which are made 2| by 1| feet 

 by 1 foot, with the ends rounded up about 6 inches. The sides 

 and ends are i-inch pine and the bottom ^-inch mesh iron wire 

 cloth, which is continued over the rounded ends. Cleats are nailed 

 on the sides, one end somewhat lower than the other, to give the 

 box a tilt when placed in water. Each box carries safely about 

 180,000 eggs, and when filled it is anchored either in running water 

 or in a sheltered cove of the lake. In the former case a current 

 of water is kept passing through the box, while in the latter the 



