136 PRACTICAL TROUT CULTURE. 



in the hatching apparatus. It is important that 

 sufficient sawdust be placed around the box in 

 which the spawn have been packed ; less than two 

 inches should never be used, and even with this 

 amount we have known the eggs to have become 

 frozen during mid-winter. A thick covering of 

 felt on the outside of the kettle has been suggested, 

 and would perhaps answer well. 



But many are desirous of avoiding the trouble 

 and responsibilities of hatching spawn, and it is 

 required that the fishes be delivered sometimes at 

 remote points. When very young fishes are de- 

 sired, we have found the best age for transportation 

 to be about fifty days after hatching. At this 

 period the yolk sac has been nearly entirely ab- 

 sorbed, its presence being only recognized by a 

 slight protrusion of the abdomen. The fishes have 

 not yet commenced to feed, and will stand a com- 

 paratively long journey with but few changes of 

 water. At this season (March and April), the 

 weather is cool, and the capacity of the water for 

 retaining air is much greater than when the tem- 

 perature becomes more elevated. Water at the 

 temperature of 50 will absorb about six cubic 

 inches of air to the gallon, while at 212 none can 

 be retained. It is therefore seen that the lower the 

 temperature the greater the amount of air that will 

 be contained in the water, and that duiing cool 



