On Stocking 



the original yolk-sac, a condition which is generally followed 

 by a suffusion of blood near the anus, and death. 



' After a fortnight's feeding on the prepared food, finely 

 ground horse-flesh is substituted. This is prepared by select- 

 ing the mash from the large chopping-machine with which 

 the food of the older trout is prepared, pounding it in the 

 mortar, and passing it through a very fine wire sieve. It is 

 then fed out through No. 9 perforated zinc rolled round a 

 circular base. This utensil we call the short feeding spoon. 

 It is found very useful, and obviates any danger of choking, 

 as all particles too large for the fry to swallow are retained 

 in the cylinder, and emptied out into a pail provided for the 

 purpose, to be mixed with the food of the yearling trout. 



* Many ingenious fry-feeding machines have been designed, 

 but as this part of fish-culture demands constant attendance, 

 and can only be successfully undertaken where the whole 

 time of at least one person can be devoted to the trout, I 

 think it unnecessary to refer to them here. The best and 

 simplest is that used at Howietoun in the experimental tanks 

 Nos. 1, 2, 3, and 4. 



' Amateur fish-culturists should, as a general rule, turn out 

 their fry ten days before the yolk-sac is absorbed. It is a 

 very common error to suppose fry will not feed until the 

 absorption of the sac. Where they are deficient of vitality 

 this may be so, but when the produce of properly selected 

 breeders, and when the eggs have been so incubated as to 

 induce great vitality in the embryos, and where the alevins 

 had suitable depth of water and sufficient current, they come 

 on the feed before the total absorption of the sac. Nature 

 has, in fact, provided them with a large reserve of food, and, 

 if vigorous, the hinder portion of the sac becomes separated 

 by constriction, and drops off under ordinary circumstances, 

 and it is only where there is an absence of vitality that the 

 sac is totally absorbed. 



1 The above does not apply to fontinalis, nor to the ova of 

 young trout, or of grilse, and even with the largest salmon 

 if hatched in water of a falling temperature, whereby the 

 period of alevinage is much prolonged, when the whole nutri- 



