106 PRACTICAL TROUT CULTURE. 



especially in a damp, cold hatching-house, is too 

 great for it to be trusted to any but faithful and 

 well-tried operators. The insufficient chopping of 

 the meat, the rubbing instead of washing of the 

 pulp through the sieve, or the throwing of it in too 

 large quantities into the troughs or trays would 

 be attended with severe loss. Like photography, 

 fish culture is composed of numerous operations, 

 the improper performance of any one of which will 

 insure failure in the end. We speak that we 

 do know, and testify that we have seen. 



The period at which the young fishes are to be 

 removed from the hatching-house varies according 

 to circumstances. If they are intended for stock- 

 ing a stream amply provided with insects, their 

 natural food, they may be turned loose as soon 

 as they have learned to feed, say two weeks after 

 the absorption of the sac ; but if for ponds, it is 

 well to keep them some six weeks longer. During 

 our first experiments in fish culture, we, follow- 

 ing the advice of others, retained them in the 

 troughs for six months, but a number escaping 

 into a pond showed by their rapid growth that 

 fresh air and exercise were equally beneficial {o 

 fishes as to other animals. Though abundantly 

 supplied with food, the fishes retained in the troughs 

 were at the end of six months less than half the 

 size of their brethren in the pond. If turned out 



