214 PACIFIC SALMON FISHERIES. 
My experiments along this line lead me to express the opinion that by the burial 
of freshly fertilized salmon eggs under 6 or 7 inches of sand and gravel strong healthy 
fry can be produced at less cost than under existing hatching methods, and that fry 
so produced are stronger and more capable of resisting the attacks of their active 
enemies. 
I trust that this short statement of my experiments in the burial of salmon eggs 
may be deemed of sufficient economic importance to stimulate fish culturists generally 
in experimenting along similar lines. Those who do will perhaps experience some 
difficulty at first in the covering of a large number of eggs. Experimenters will find 
that after preparing suitable beds of sand and small gravel the eggs can be evenly laid 
and held until covered, if the surface of the bed is first thickly indented with cells a 
little deeper than the eggs. This can be readily accomplished by stamping the bed 
with a board covered with projections or pegs of suitable size. 
My experiments suggest that in the near future most of the buildings and hatching 
apparatus now used in the propagation of salmon and trout will be dispensed with; 
that after the eggs have been expressed and fertilized, instead of being placed in wire 
baskets in hatcheries, they will be buried beneath the sand and gravel of the beds of 
natural or prepared streams, and that with the exception of watchmen to protect 
them, little or no other labor will be required.2 
FEEDING AND PLANTING THE FRY. 
For some time the fry remain at the bottom of the trough, but 
when the yolk sac is nearly absorbed they rise from the bottom and 
begin swimming. As a rule the fry are planted about the time the 
yolk sac is absorbed, thus obviating the necessity for feeding them. 
Some experts advise planting young red salmon when the umbilical 
sac is about two-thirds absorbed, which is the time when the fish 
begin to swim up freely. With the temperatures prevailing at the 
Alaska hatcheries, this means that the fry must be held at least four 
or five weeks after hatching. 
PACKING EGGS FOR SHIPMENT. 
In packing salmon eggs for shipment it is the custom at the Bureau 
of Fisheries’s hatcheries to use a packing box made of one-half inch 
pine, 2 feet square and 1 foot deep.® 
At the bottom is placed a thick layer of moss, then a layer of mosquito netting, then 
a layer of eggs, then mosquito netting again, then successive layers of moss, netting, 
eggs, netting, and so on to the middle of the box. Here a firm wooden partition is 
fastened in and the packing renewed above in the same manner as below. The cover 
is then laid on the top, and when two boxes are ready they are placed in a wooden 
crate, made large enough to allow a space of 3 inches on all sides of the boxes. This 
space is filled with hay to protect the eggs against changes of temperature, and, the 
cover being put on the eggs, they are ready to ship. In the middle of the crate an 
open space about 4 inches in depth is left, between the two boxes of eggs, for ice. 
As soon as the crates arrive at the railway station this space, as well as the top of the 
crate, is filled in with ice. Recent experiments show that salmon eggs can be packed 
and safely transported to considerable distances when they are first taken. 
« Some experiments in the burial of salmon eggs—suggesting a new method of hatching salmon and 
trout. By John Pease Babcock. Trans. Am. Fish. Soc., 1910, p. 393-395. Washington, 1911. 
b A mannal of fish culture, based on the methods of the United States Commission of Fish and Fisheries. 
Revised edition, p. 14. 
