Laboratory Exercises 381 
(g) The white yolk and the dark yolk showing its concentric 
layers. (h) The germinal disk. (¢) The chalaza (‘ hammock 
cords ’’). 
51. PRESERVING Eaes 
Object. To preserve eggs. 
Materials. One pint ““N”’ grade silicate of soda (waterglass) ; 
one two-gallon earthen jar; several dozen of fresh eggs. 
Directions. Select clean, unwashed eggs. Wash out the jar 
in boiling hot water. Fill the jar with the eggs to within 2 inches 
of the top. Dilute the waterglass in nine times its bulk of water. 
Pour this mixture into the jar of eggs until all of the eggs are well 
covered. Cover the eggs with a plate to keep them below the 
level of the waterglass. Cover the jar and set in a cool cellar. 
Visit the jar every month to replace the water which has been lost 
through evaporation. 
