MANUAL OF FISH-CULTURE. 87 



iu the bottom of the box to a depth of about 3 inches and the crate 

 of trays placed as near the center of the box as possible. The sides 

 are well packed to hold it firmly in position, and when the top of the 

 hopper is reached witli the packing it is well filled with ice, the remain- 

 ing space iu the box being filled with moss. Wet moss or wet packing 

 of any kind should never be used for the cushion around the egg-crate, 

 as it does not jjreserve an even temperature and is liable to freeze solid 

 if exposed to a low temperature iu transit. A cross-section of the 

 box thus packed is shown on page 84. 



The box containing the eggs should be provided with handles to 

 facilitate moving during transportation, in order that the liability to 

 injury from jarring or concussion may be reduced. For a long journey 

 the lid of the box is i^rovided with hinges and hasp and staple, so that 

 the ice may be easily renewed. Eggs packed as described above have 

 been shipped with safety to all parts of the United States and to for- 

 eign countries. 



DISEASES OF FRY AND ADULTS. 



The most common diseases of trout fry are the inflammation of their 

 gills and a slimy skin disease, which may be caused by impure water; 

 the food itself may produce it, especially if stale liver is used, but it 

 generally follows fouling of the water while feeding. By watching 

 the movements of the fish, the symptoms of disease can generally be 

 detected before it reaches an alarming stage. If the gills are affected 

 the fish will usually swim high iu the water in an uneasy, restless man- 

 ner, as if gasping for breath, and when this is observed the gills must 

 be examined to see if they are becoming inflamed and swollen. If a 

 skin disease is attacking the fish, they generally indicate it by rubbing 

 themselves on the bottom of the trough or against anything that may 

 be convenient, or by diving down and giving themselves a quick, twist- 

 ing motion against the bottom of the trough. If the progress of dis- 

 ease is not promptly checked, it will soon reach a stage where nothing 

 can be done, and the fish grow weaker every day until they begin to 

 die iu alarming numbers. One of the best remedies for both diseases 

 is salt sprinkled through the water after the ponds are drawn low, and 

 for a bad case of skin disease a half pint of salt for every gallon of water 

 in the trough is used, or about that proportion. The fish should be 

 watcht^d closely and allowed to remain in the salt water until they 

 become restless and begin to turn on their sides. Then, as fresh water 

 is turned on and the trongh fills, a slime will arise and float on top of 

 the water, like a white scum. Coarse sand should be kept in the trough 

 for the fish to rub themselves against. Salt is also good for the dis- 

 eased gills and will free them from adhering sediment. 



Fungus, "blue swelling," and other diseased conditions sometimes 

 occur, but the most serious diseases of the fry are those just described. 

 Parasites sometimes attack the fish, but if the water is pure and the 

 fish in a healthy condition, they are not troublesome. To keep the fish 



