a favorite locality for depositing their eggs the parts of 

 the bottom of the ponds or streams through which a 

 spring made its way. Nature taught them thus, to 

 secure a regular flow of clear, unpolluted water of even 

 temperature, working its way between the gravel and 

 eggs of which their nests were composed, and much larger 

 percentage of the spawn deposited in such places hatched 

 than when it was under any other natural conditions, for 

 it was certain to receive precisely what it needed, a 

 steady cjurrent of fresh and well aerated water, not in- 

 creased or diminished in volume, not fouled by rains, not 

 warmed by the sun or cooled by frost, and not hearing 

 ■with it the germs of fungus or disease. Changes of tem- 

 perature or condition are injurious to spawn, and hy this 

 plan, changes are avoided. 



Holton in the arrangement of the hatching box which 

 he invented, created an artificial spring of great volume, 

 conveniently located and thoroughly under control. It 

 was impossible to deposit the eggs over the natural 

 springs, so the springs were brought into the hatching 

 house. This was done by leading the water properly 

 screened through a pipe into the bottom of a box, and 

 allowing it to pass out over the top. A deflector was 

 placed over the aperture in the bottom so as to break the 

 current and distribute the flow equally in all directions, 

 and trays were laid, one upon another in the .box so that 

 the water would have to rise through them all before it 

 could escape, and the eggs being on these, must neces- 

 sarily be kept directly under the influence of a steady 

 but gentle and natural current. 



These boxes were constructed especially for the incuba- 

 tion of white fish and shad eggs,, although salmon, salmon 

 trout, etc., can just as well be hatched with them. They are 

 about twenty inches square and two feet deep, and will 



