American Fisheries Society. 105 
do not usually read above 1.030. The highest of the usual series 
of three may sometimes be used for whitefish. The trials were 
made by immersing the tray itself with the eggs upon it in the 
salt solution. 
“Evidently the temperature of the salt solution need only be 
such as not to injure the eggs by the temperature change. The 
temperatures of the solution actually used was between 43° F, 
and 52° F., and the eggs were taken from tap water at about 
42° F. 
“In no case did any injury appear from the action of the salt 
solution. 
“The densities given here as correct for a given species need 
not necessarily be rigidly adhered to. In practice at different 
stations a somewhat different density may be preferable on ac- 
count of the variation in lots of eggs from different sources, and 
the specific gravity instruments or hydrometers used may not 
correspond exactly. In these trials the density was taken in a 
glass cylinder, and the hydrometer was read by reviewing the 
scale from below the surface and not by the water which creeps 
up the stem above the surface. If in practice it is more con- 
venient to float the instrument directly in the tank or box of 
salt solution the observer can not take the reading in this way 
but may adopt any uniform method, remembering that this will 
introduce another slight variation from the densities given above. 
“Lake, brook, or rainbow eggs, recently dead, in which the 
embryo but not the egg has turned white, do not separate well 
from the live eggs. 
“From a lot of eyed lake trout eggs arriving at Central sta- 
tion January 16, and containing a number of dead eggs, about 
70 per cent. of the dead eggs were separated January 16 by a 
1.068 solution. A few live eggs were contained among the dead 
removed from the surface of the solution.” 
Tt will be observed that no laboratory tests were made to dis- 
tinguish dead or unfertilized eggs at early stages of development. 
If this feature of Mr. O’Malley’s discovery is practical with eggs 
of other species than those already tested—notably those of the 
brook trout and lake trout—it will facilitate the preparation of 
eggs for long distance transportation, or for shipments to for- 

