6. Explain how a developing chick breathes.
7. What new organs are first seen distinctly on the fourth and fifth days respectively of incubation of a hen’s egg? Explain exactly how you would expose them to view, and describe their appearance.
8. What is the period of incubation of a duck’s egg? Observe and describe exactly how the hatching duckling breaks open the shell and escapes from it.
9. Observe and describe a duckling’s first attempt to swim. Is the action instinctive or not?
10. Make other observations upon ducklings, comparing them in as many respects as possible with chicks, and write careful accounts of the results you obtain.
11. How does a fowl’s egg which has been hatched for four days differ from a fresh-laid egg? Describe the new structures which have formed in it, so far as they can be made out by the unaided eye. (1904)
12. Where does the chick begin to form in the egg? Explain the arrangement which brings it as near as possible to the body of the sitting hen. (1905)
13. What is the use of the cloudy masses attached to opposite sides of the yolk of a fowl’s egg? (1906)