158 How to obtain it. 



with grilles. Never half fill one, and lay down ova before putting 

 in all the grilles. There would be a danger of disturbing the eggs 

 in the lower half of the box, whilst placing grilles, etc., in the 

 upper. Many persons would probably say that they could do it 

 quite easily without doing the slightest harm, and I have no doubt 

 they could but there is no object to be gained, and harm may 

 be done. It is one of those points the observance of which tends 

 towards success, and I would not give much for the results from a 

 hatchery where such rules were not strictly observed. 



In laying down the eggs always commence at the lowest end 

 of a set of boxes,- and go on filling as the ova comes into the 

 hatchery, until that set or series of boxes has received its full 

 complement of ova. In a large hatchery it is sometimes desirable 

 to have several sets of boxes filling at the same time. This does 

 not matter. The object is that as the eggs are laid down, so shall 

 they hatch in rotation, and it would be bad policy to arrange to 

 have some hatching in one of the upper boxes, whilst others were 

 being incubated in a box below. 



There will probably be a few white eggs, and these should 

 be picked out. This may be done either before they are laid 

 down or after, or if the former course be taken both before and 

 after, for some will probably turn white either whilst being laid 

 down or very soon after. They are easily picked over whilst in a 

 bowl or other vessel, as owing to a slight difference in the specific 

 gravity, the white eggs rise to the top when slightly agitated, 

 either by pouring in water or by means of the hand. The reason 

 why some of them turn white is that they have absorbed water, 

 which acts on the albumen of the egg, causing a white precipitate 

 to form and this goes on more or less during the whole time of 

 incubation. Where a good impregnation has been secured there 

 will not be many white eggs. It is the badly impregnated and 

 unimpregnated ova that turn white as soon as the water percolates 

 the shell of the ovum. Some unimpregnated or " blind eggs " 

 remain unchanged until all the others are hatched. These will 

 do no harm, and may either be picked off any time at leisure, or 

 left until all the hatching is completed, when they can be 

 removed with the grilles. 



A variety of implements have been used for the purpose of 



