142 Modern Fishculture in Fresh and Salt Water. 



lost all disposition to lie on the bottom of the can, 

 where they are liable to be killed by continuous shocks 

 and bruises. Until the sac is nearly gone they cannot 

 bear handling, but they grow stronger as the umbilicus 

 is absorbed. 



In taking fry, as well as adult fish, great care must 

 be taken of the two vital points temperature and aera- 

 tion. The temperature may be kept down by ice, or, 

 better yet, snow, for ice, if in large pieces in the cans, 

 will crush many fish, while snow is soft ; an ice tray in 

 the top of the can is best. 



As the trout exhaust the oxygen from the water 

 more must be supplied. This is done in several ways; 

 by using a dipper and pouring the water a foot or more 

 through the air ; by drawing off a pailful through a 

 siphon which has a strainer of perforated tin or of 

 cheese-cloth in the upper end, and thenjpouring it 'back 

 and forth in another pail a few times and returning "it 

 to the can. With ten cans these ways are too labor- 

 ious, while an air pump is useless unless you have a 

 fine strainer in the bottom to divide the air and keep it 

 from coming up in large bubbles, which do little good, 

 and the labor is too much. I prefer such a brass 

 syringe as greenhouse men use for spraying plants, with 

 a fine "rose" sprinkler on the end ; one and a half inches 

 in diameter and twelve to fourteen inches in length. 

 This is lighter and easier to carry than any of the other 

 implements and is as effective ; fill the cylinder, raise it 

 a foot above the water and drive the fine streams down 

 into the can. At a temperature of 40 Fahr., three in- 

 jections to each can every half hour when not moving 

 should keep the fish at the bottom, for when they are 

 suffering for air they will crowd to the surface for -it. 

 When they do this it will take continuous work for an 



