How to obtain it. 173 



found a very good plan to have at least one spare hatching box. 

 It can be made ready to receive the grilles from another 

 box. This box may then be cleansed, and made ready for 

 those from the next, and so on, right through the hatchery. 



Thus the fish or " alevins " as they are called at this stage, 

 have perfectly clean boxes in which to commence life, a most 

 important matter considering the extremely delicate mechanism of 

 the little creatures. More than this, it will be found, in prac- 

 tice, that on emerging from the egg they slip through between the 

 glasses of the grille, and find their level on the bottom of the box, 

 whereas the egg-shells remain where they were, with the ex- 

 ception of a few which are carried over the end of the grille by 

 the " alevins," in their efforts to escape from their prisons. They 

 are, therefore, at once separated, and all being hatched, the grille 

 -can be lifted out with the shells upon it and the fish will be found 

 underneath it, packed together, somewhat reminding one of a 

 swarm of bees. The eggs can all be hatched in a few hours, by 

 regulating the temperature of the water, and in a large hatchery 

 .this is a matter of importance, and due provision should be made 

 for it. All that is necessary is to raise the temperature a few 

 degrees in the boxes in which the eggs are on the point of hatch- 

 ing. They can then be hatched off, and the shells lifted out with 

 the otherwise empty grilles. There is no trouble from clogging 

 of screens or anything else. The few shells which remain in the 

 .box may be left for the present, and will do no harm. Put on the 

 lid and leave the whole affair till the next day. 



The egg-shells remaining may then be cleared by drawing 

 .the plug behind the screen at the end of the hatching box, and so 

 inducing an extra current. The water supply may or may not be 

 stopped, according to the will of the operator, as he may find 

 best. In either case the result will be the same the water will 

 be lowered and so lessened in bulk, the current will be increased, 

 the " alevins " will remain packed, and the shells will be carried 

 on to the screen. Care should be taken that the box is not so far 

 drained that the fish are left uncovered even for a moment. After 

 re-inserting the plug the water rises, and a bowl should be brought 

 .alongside and placed on a table which, when not in use, is kept 

 under the hatching boxes 



