742 BULLETIN OF THE BUREAU OF FISHERIES. 



USUAL STYLE OF PACKING CASE. 



For ordinary purposes a packing case consists of a wooden box which will 

 accommodate a stack of trays and an ice hopper, with 2 to 4 inches of insulation 

 or packing on all sides and under the tray stacks. The frames of the trays are 

 made of light, soft wood, usually white pine, ^ inch by yi inch or 14, inch by 

 yi inch, over which is tightly stretched a bottom of canton flannel, nap side up, 

 or of heavy cheese cloth, with perforations in the cloth to facilitate the passage 

 of water. 



For long-distance shipments it is customary to make the bottoms of the 

 trays of wire cloth painted with turpentine asphaltum, over which canton 

 flannel or cheese cloth may be spread before putting the eggs upon them, and 

 a thin layer of moss under the cheese cloth in addition is advocated by some 

 fish culturists. The soft spongy bed of moss prevents concussion in handling 

 and retains moisture, while at the same time it allows a sufficient circulation 

 of oxygen and free passage for water from melting ice, etc. For very long or 

 warm-weather shipments it is sometimes advisable to use a case with double 

 sides, with insulation between, the space between the inner case and stack of 

 trays being filled with ice. 



The ice hopper is about 3 or 4 inches deep, of the same length and width as 

 the tray frames, and rests upon the top of the stack. Its bottom is perforated 

 to allow a drip from the ice through the trays and thus keep the eggs constantly 

 moist and cool. Double cases, the length twice the width, arranged for two 

 stacks of trays side by side with a partition between them, are sometimes used 

 in the Pacific salmon work. 



The fish culturist often works in isolated places and must use the material 

 which is most accessible and economical. Mossr is therefore very generally used 

 for filling the space between the stack of trays and the packing case; mineral 

 wool, leaves, sawdust, and shavings also well serve the same purpose, though 

 with ice in contact with the inside lining of the outside case mineral wool is 

 objected to because when damp it has a tendency to sag. Any of these materials 

 may be used for insulation in the long-distance cases. Cork board insulation, 

 also, is very efficient and of lighter weight than the others, but it has not been 

 tested so fully as have shavings, at present the material most popular with 

 caretakers. 



The cover to the case may be screwed on, but for shipments requiring the 

 renewal of ice it is customary to provide a hinged cover fastened with hasp and 

 staple. 



ADAPTATIONS AND VARI.\TIONS OF METHOD. 



Eyed eggs of the Atlantic and Pacific salmon and of the steelhead trout 

 have all been successfully shipped in the ordinary case, but the method of packing 

 eggs of the Atlantic salmon at the Craig Brook (Me.) station has the special 



