{11] PROPAGATION OF WHITEFISH AT NORTHVILLE, MICH. 563 
ture of 33° in air or water, but not lower in air, the farther their removal 
from danger. Knowing that good results depend largely upon the near 
observance of these ‘first principles,” the operator must be governed 
accordingly, remembering that the object of taking eggs is to hatch fish ; 
that fish can be hatched only from live, impregnated eggs, and therefore 
it is better, under all circumstances, to strive not so much to see how 
many but how well they can be taken and taken care of. A half million 
eges secured in this way will produce more fish than a million carelessly 
taken and indifferently cared for. 
FLOATING BOXHES. 
The floating boxes referred to in the following tables are a simple con- 
trivance for retaining the eggs for a short time at the spawning grounds, 
and are usually made of the following dimensions: Twenty-four inches 
in length by fifteen in width and twelve in depth, having a screen- 
wire bottom, and wide boards fastened edgewise to the ends to insure 
their floating. For the safety of the eggs they should be placed in har- 
bors, or some suitable place protected from violent storms or heavy 
seas. In the present instance they were floated under the docks, whence 
they were not subjected to the force of sharp seas, and yet were suffi- 
ciently influenced by the smaller waves and tide-currents to give the 
eggs constant changes of water. As the presence of dead (or unimpreg- 
nated) eggs is not specially hazardous to the others, previous to fungus 
growth, and as this growth seldom, if ever. appears on eggs less than 
seven days old, and usually ten to twelve—depending, of course, on 
the temperature of the water—their removal during this period is not 
material, and for this reason the floating boxes are found very conven- 
ient for retaining the eggs until a sufficient number for shipment has 
accumulated, requiring no special care in the mean time. 
