Trout Breeding. 53 



suspend it in any other way. This is to stop all gam- 

 marus or plants, which may clog the lower screen but 

 cannot clog this one because it is above high- water level. 

 Gammarus are good trout food, but are not desirable in 

 troughs, because they may kill delicate embryo trout, 

 although they do not seem to hurt the eggs. They are 

 scavengers, and will eat a dead embryo ; but it is best 

 for the. fishculturist to be his own scavenger in the 

 troughs. 



At the lower end of the trough arrange to carry your 

 outflow straight under the floor or back under the 

 trough, as may be convenient ; but I prefer to have the 

 cutlet hole in the bottom, and not in the end of the 

 trough. Put a one and one-half inch ''sink plug," to be 

 obtained of a plumber, two inches from the end, first 

 filing out the cross bars ; then throw away the stopper. 

 A short tin tube soldered to the lower end will prevent 

 all slopping over into the pipe which takes away the 

 water. 



An inch above the hole put a one-half inch strip on the 

 sides to hold a dam ; and an inch above this put two sim- 

 ilar strips for the outlet screen to slide in. Three small 

 wire brads will hold the strips in place. See cut on 

 page 46, which shows how the end of the trough is 

 let in. Some carpenters prefer to let the sides and 

 bottoms of troughs project an inch beyond the ends, 

 but that is one of those minor matters of detail that 

 are not of enough importance to argue about. 



Now make your one and one-half inch dams, and also 

 some six-inch dams to fit the same place, and mark them 

 with a chisel with the number of the trough, for they 

 must be water-tight on bottom and sides. The narrow 

 dams are to be used until hatching begins, and then the 

 deeper ones are to be put in, and the screens also. Fit 



