198 SPORT IN NORWAY. 



width of the case by means of two pieces of wood, 

 which are fastened to the sides, and reach nearly to 

 the middle, and is carried off by a pipe. 



The slimy deposit which comes even from the purest 

 water, and settles on the eggs (it is not detrimental 

 unless there be too much of it), can easily be got rid of 

 by gently moving the boxes, and allowing it to pass 

 through the ends. 



After the lapse of about four weeks it will be well to 

 take the hatching-boxes out of the case to ascertain 

 which eggs are good. The action of the air will render 

 them all transparent ; but on replacing them in the 

 water, the unfruitful ones will assume a milky opaque 

 colour. These can readily be removed with a pair of 

 fine pincers or long tweezers. The exposure to the 

 air does not hurt the eggs, but care must be taken 

 that they do not become dry on the surface. After 

 repeating this process three or four times, all the bad 

 eggs can be removed. "I am convinced," is the 

 remark of Professor Easch, "that in a case of the 

 above size I could hatch 10,000 salmon ova in each 

 box, which would thus give a total of 160,000," there 

 being four hatching-boxes in each of the four compart- 

 ments. If the fry are to be kept any time in the boxes, 

 care must be taken that they be not overstocked ; but 

 3,000 may well be kept in them from two to three 

 months." 



