30 GROWTH OF EGGS, &C. 



than those hatched in fifty days at fifty degrees. It may 

 be well, also, to note that the eggs earliest taken will pro- 

 duce the best fish. The water of a spring can be reduced 

 in temperature in winter by letting it run for a short dis- 

 tance exposed to the open air. 



Growth of Eggs, &c. — A.bout the twentieth day, the 

 young fish can be plainly observed in the egg. Put a few 

 eggs in a small vial and with a magnifying glass the form- 

 ation of the fish can easily be seen. Fish farmers send the 

 eggs away at this time. Some of the eggs are not impreg- 

 nated and at this stage of growth may easily be distin- 

 guished from the others as no fish forms in them. The 

 dead eggs will turn to a milk or pearl white color, and 

 should be removed with the nippers as fast as they are dis- 

 covered. If left in the trough a fungus growth forms 

 upon them which extends to other eggs in the immediate 

 vicinity and kills them. Care should be taken in using 

 nippers, not to hurt the other eggs ; a very slight blow or 

 jam from the nippers will be sufiicient to destroy their 

 vitality. Rats and mice in the hatching house often des- 

 troy many eggs ; they are very fond of them and going into 

 the troughs to get them they will destroy with their feet 

 many more than they eat. A wire screen laid over the 

 troughs will keep them out, but it is a much cheaper and 

 just as aifectual a way to keep them down by traps or 

 poison. The eggs should be feathered over occasionally 

 so that their whole surface may be exposed to the action 

 of the water. 



Transportation of Eggs. — We pack eggs in round tin 

 boxes, about three inches wide and two and one half inches 

 deep ; a few small holes are punched in the bottom to let 

 the water run ofi", as water left in the box will kill the 

 eggs. Specimens of eggs from difierent parts of the square 

 are first exauiined with the microscope to see if a good per 



