ARTIFICIAL IMPREGNATION. 85 



pan should be kept at an even temperature. The 

 nursery troughs in our hatching-house are well 

 suited for this purpose, keeping it at the constant 

 temperature of 50. Be in no hurry to transfer 

 the eggs from the pan to the hatching troughs or 

 trays the process of impregnation is soon accom- 

 plished ; but the eggs are very easily injured at 

 this period ; and when the temperature of the 

 water can be kept constant, half an hour's repose 

 should be allowed them before the transfer takes 

 place ; then gently pour them, after thorough 

 washing, on the spots where they are for some time 

 to remain. Should they be heaped, gently, with a 

 feather, or better still, a broad camel's hair brush, 

 distribute them evenly upon the grille of the tray 

 or the gravel of the trough. The washing is not 

 absolutely necessary for the health of the spawn ; 

 yet the water being rendered somewhat opaque 

 by the milt, its removal will enable the operator 

 to see his way much more clearly. The eggs 

 should so lie that they in no case be heaped one 

 upon the other. Touching does no harm, but we 

 have in many cases found heaping fatal. In mov- 

 ing the eggs we again say, be gentle ; the time will 

 come in the life of the egg when it will bear rough 

 handling, even the handling of the express agent, 

 whose mercies are by no means tender; but the 

 time is not yet. Gentle movement beneath the 



