Vlll PEEFACE. 



difficult a study, so recondite in its secrets, so 

 partial and uncertain in its results, that it should 

 not vie, by the means of study and experiment, 

 with agriculture? Surely the small results 

 already obtained do not tell us so ; much rather 

 do they encourage us to pursue our inquiries, 

 that we may win from Nature her secrets and 

 profit thereby. We know something of the 

 science, but the main secrets remain to be 

 explored. 



People are apt to consider the hatching of fish- 

 ova a very difficult, astonishing, and precarious 

 operation. It is natural that they should do so, 

 as the process is new to them. But there is 

 no real difficulty in the matter; any one can 

 compass it. The appliances are of the simplest 

 kind. Indeed, I would undertake to hatch a 

 hundred young salmon with the aid of a cheese- 

 plate and a tumbler of water. But the point 

 chiefly to be considered is, how are fish to be 

 fed and fattened when they are hatched ; what 

 suits them, and what does not? We often 

 hear of the fish in certain waters dying off 

 without bein^ able to discover the cause. Some 

 weed, or insect, or other matter which is very 



