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tittle of their exactions, so when man steps in he upsets 

 the scale and tumbles the whole shad fishery into con- 

 fusion and ruin. It requires a greater annual contribu- 

 tion to keep up the yield than with trout ; it falls off 

 proportionately greater when this contribution is cut 

 down. 



ARTIFICIAL METHOD. Shad eggs differ essentially 

 from trout eggs and require wholly different manipula- 

 tion. They are much smaller and lighter. If a trout 

 or salmon egg is dropped into water it sinks at once to 

 the bottom, but a shad egg will almost float, and has but 

 little more specific gravity that the water itself. Shad 

 eggs are less than half the size of trout eggs and require 

 as their best condition for hatching a temperature of from 

 sixty-five to seventy-five degrees. They will hatch at a 

 lower temperature but in such cases mature slowly, 

 while eighty degrees of heat is as much as they can endure. 

 When experiments were first made in their artificial 

 propagation they were placed in ordinary trout troughs 

 and much trouble was found in their management. If 

 a current of water was turned on to the same extent as 

 with trout they all washed over the end of the troughs, 

 while if the supply was diminished so that they retained 

 their places they died of suffocation. It was only after 

 many different devices had been tried that the proper 

 invention was discovered a simple box with the bottom 

 knocked out and replaced by a wire gauze netting. This 

 box is suspended by floats of wood nailed on the sides 

 so that the bottom is presented at an angle to the cur- 

 rent, the degree of inclination being determined by the ve- 

 locity of the current. The water striking against the screen 

 enters the minute interstices, and lifting the eggs keeps 

 them in gentle motion like the bubbles of air in a pot of 

 moderately boiling water. All that is necessary is to 



