'64 XJ. S. BUREAU OF FISHERIES. 



side of the case, around the sides, and at the bottom of the stack of 

 trays, is a one-half-inch air space, the air entering through four 

 holes bored through the walls, one on either side near the bottom, 

 one at the front, and one at the back under the ice pan. The case 

 is provided with strong iron handles, and the lid is put on Avith 

 four hinge hasps with drop fastenings, these being more satisfactory 

 than common hinges. 



The trays of eggs are held in place by V-shaped grooves formed by 

 nailing cleats of suitable size in the corners of the case and are 

 supported by four small blocks nailed to the bottom in the corners. 

 Covering the bottom of the case and extending up 1 inch on all 

 sides is a lining of tin, and through the center of the bottom is the 

 drain tube. The ice pan, of galvanized iron and about 4 inches deep, 

 fits the inside of the case. Its bottom is perforated to correspond 

 with the inside dimensions of the egg trays, so that water from 

 the melting ice contained in the pan must pass downward through 

 the trays of eggs and escape through the tube at the bottom of the 

 case. 



After arranging the stacks of egg trays in the case the ice pan 

 is set in position over them, filled with broken ice, and covered with 

 a piece of oilcloth. A cushion or pillow of dry sphagnum moss is 

 fitted into the space between the ice and the lid of the case ; the lid 

 is then closed and the eggs are ready for shipment. 



DISTRIBUTING AND PLANTING FRY AND FINGERLINGS. 



Rainbow trout from the bureau's hatcheries are distributed to 

 applicants either as advanced fry immediately preceding the feed- 

 ing stage or as fingerlings, after two or three months of artificial 

 feeding. They may, however, be planted successfully at any time 

 after the absorption of the yolk sac in waters where conditions are 

 favorable. In the Southern States the best time for planting is the 

 middle of March. In the more Northern States the springfed 

 streams and open lakes are usually in condition to receive plants 

 of fish in April. In any locality where the new green of the 

 meadows and woods indicates the advent of spring the young fish 

 may be safely planted. In their natural habitat the rainbows spawn 

 during the early spring, and the young have absorbed the sac and 

 are ready for food late in May or by June. Practically all of the 

 fish hatched during the winter months at stations of the bureau are 

 held and fed until weather conditions are favorable. 



In making deliveries of fish to applicants, the ordinary 10-gallon 

 milk can of the commercial dairyman is used. The number of fish 

 that may be carried safel}^, per can, is dependent on the size of the 

 fish, temperature of water, and the distance to be covered. In well- 

 aerated water of a temperature ranging between 48 and 55°, the 

 following numbers may be carried safely in a 10-gallon milk can : 



Advanced fry, at feeding stage 2, 500 



Fingerlings No. 1__ 1, 000 



Fingerlings No. 1^ 600 



Fingerlings No. 2 300 



Fingerlings No. 2i 150 



Fingerlings No. 3 100 



