PEEVENT EVIL CONTIGUITY. 



385 



After the roe becomes fructified by the milt, the case of 

 grilles, Fig. 2, is placed in the tray, and then deposited cross- 

 wise in the race-way, where the tray is mechanically confined, 

 when the ova is emptied on the glass grille, and left for nature 

 to do the rest, only seeing that the water continues to form a 

 stream like a natural brook through the race-way, and that 

 the light be never glaring or the temperature of the water 

 too high, bearing in mind that there will be several degrees 

 of difference between the water at the head and foot of the 

 way. 



The grilles should be examined daily, and any addled or 

 dead eggs removed from contact with others. This should 

 be done so as not to disturb the other eggs, as great quiet 

 during the months of incubation is necessary. 



The following cut represents the implements for removing 

 dead eggs. 



Fig.l. The Siphou, used for examining the eggs. 2. Pincers for picking out dead eggs. 

 3. Fine brass wire for taking up dead eggs. 



The siphon is used in France to draw , up the dead eggs ; 

 but, as it generally disturbs so many of the live ones, its gen- 

 eral use in fish-culture is now confined to examining the eggs, 

 while pincers with sharp-pointed nibs are often used for pick- 

 ing out the dead eggs ; but Mr. Francis states in his " Fish 

 Culture" a small but very useful volume "Some use a 



BB 



