Figure 5.—Egg at End of 120 Hours.
As a rule, in our machines, we introduce one moisture pan about the 18th day for both duck's and hen's eggs. It makes some difference whether a machine is run in a humid atmosphere near the seashore or in a dry, rarified atmosphere at an altitude in the country.
Figure 5 represents the egg at the end of the fifth day, the circle enlarged, shaded darker in color; the whole egg being slightly darker in hue.
Figure 6, at the end of the sixth day, shows still more plainly the germ undergoing a gradual change in the egg, enlarging and assuming a darker hue. The outline of the circle is now gradually acquiring the form of an ellipse, and in a live embryo the line of demarkation should be distinct. If it is at all wavy and irregular in its outline, and instead, remaining intact, the contents of this ellipse show a disposition to assimilate with the surrounding liquids when the egg is revolved, it can be safely removed as a dead duck.
