REARING YOUNG SALMONOID FISHES. 227 



the practice to place thcin on small "feeding boards" of special construction suspended 

 over the water in the troughs and let them crawl off into the water; but whatever 

 advantage this method may have had in furnishing the meal to the fish slowly was more 

 than counterbalanced by the extra labor of caring for the boards and by the offensive 

 odor, and it was abandoned. For use in feeding fish in a pond a box containing a 

 series of shelves, adown which the maggots slowly crawl, was found sufficiently useful 

 to be retained. 



It is the common practice to feed all meat raw except the lights, which chop bet- 

 ter if boiled first, except also occasional lots of meat that are on the point of becoming 

 tainted and are boiled to save them. All meats fed direct to the fish are first passed 

 through a chopping machine. The machine known as the "Enterprise" is the one 

 now in use. It forces the meat through perforated steel plates. The plate used for 

 the smaller fish has perforations ^ 2 - inch in diameter, and for coarser work there are 

 two plates -1% inch and g inch, respectively. It is operated by a crank turned by hand. 

 Food is given to those fish just beginning to eat four times a day (in some cases even 

 six times). As the season progresses the number of rations is gradually reduced to two 

 daily. In winter such fish as are carried through are fed but once a day. 



The cleaning of the troughs has been a troublesome matter, and the subject of 

 much study and experiment, but nothing more satisfactory has been found than the 

 following practice: The troughs are all to be cleaned daily — not all at one time, but 

 as time is found for it in the intervals of other work. To facilitate cleaning, the 

 troughs are inclined about 2 inches. The outlet is commanded, as already explained, 

 by a hollow plug. When this is drawn the water rushes out rapidly and carries most 

 of the debris against the screen. The fishes are excited, and, scurrying about, they 

 loosen nearly all dirt from the bottom; what will not otherwise yield must be started 

 with a brush, but after the first few weeks the brush has rarely to be used except to 

 rub the debris through the outlet screen. Owing to the inclination of the trough the 

 water recedes from the upper end until the fishes lying there are almost wholly out of 

 water, but, although they are left in that position sometimes for 10 or 15 minutes, no 

 harm has ever been known to result. 



It has been the common rule at the station to count all the embryos devoted to the 

 process of rearing, either before or after hatching; to keep an accurate record of losses 

 during the season, and to check the record by a recount in the fall. When eggs are 

 counted they are lifted in a teaspoon. 



The counting of small fish is effected in this way: The fish are first gathered in a 

 fine, soft bag-net, commonly one made of cheese-cloth, and from this, hanging meanwhile 

 in the water, yet so that the fish cannot escape, they are dipped out a few at a time, 

 in a small dipper or cup, counted, and placed in a pail of water or some other recep- 

 tacle. This counting is generally preliminary to weighing, and in this case the fish, 

 after counting, are placed in another bag-net, in which they are lowered, several 

 hundred at a time, into a pail of water which has been previously weighed, and the 

 increase noted. With care to avoid transferring to the weighing pail any surplus 

 water, this is a correct method and very easy and safe for the fish. 



In conclusion, I submit some estimates of cost. In September, 1893, we fed fry 

 that were estimated at the close of the month to number 238,300. There were also a 

 few hundred larger fish. From the known total outlay for food, attendance, and 



