64 DOMESTICATED TROUT. 



should be tacked over this opening, so that there can 

 be no danger of anything getting in there and if the 

 covers do not fit down tight, they should be hooked 

 down, or caught with a spring. When the carpenter 

 puts on the covers, examine them carefully, and see 

 that there are no chinks to admit even a lizard. If 

 there are not, then your hatching boxes are complete 

 in every respect, and, if the previous suggestions have 

 been carried out, will do their work to your perfect 

 satisfaction. 



I have proceeded thus far on the supposition that 

 troughs of carbonized wood or other material are used. 

 For the guidance of those who prefer glass grilles I 

 quote the following remarks upon them from " Harper's 

 Magazine " * and from Dr. Slack's Catalogue of fish 

 culturist's apparatus. 



" The Coste Hatching Tray (glass grilles) consists of 

 a trough (made of earthen-ware, glass, or slate) about 

 two feet long, six inches wide, and four inches deep. 

 On the inside, about two and a half inches from the 

 bottom, are small projections, upon which rests a glass 

 grille, a species of gridiron formed of glass tubes 

 placed closely together, the ends being confined in a 

 wooden rack. There is a spout on one side and at 

 the top of the box to run off the surplus water ; at the 

 bottom and below the level of the grille are two other 

 openings, usually stopped, but convenient to open in 

 order to remove the sediment which from time to 

 time collects. In using these hatching boxes water 

 can be supplied from a water-cooler through a filter, 

 * Harper's Magazine, November, 1868, pp. 728, 729. 



