CHAPTER VIII 



THE BIRD WITHIN THE EGG 



IN writing of birds, as of other subjects, it is logical 

 to begin ab ovo. This system, however methodical 

 and German it may be, I have deliberately avoided, 

 since in practice it is unwise to begin with what is 

 least intelligible. Now that the reader understands 

 the circulation of the blood, he will more easily under- 

 stand some important points in the development of 

 the embryo. If the pages that describe the circula- 

 tion are not fresh in his memory, he is recommended 

 to look them up before reading this chapter. 



If a sitting hen be watched upon her nest, she 



may sometimes be seen to raise herself a little, and 



stir the eggs with her feet. Many people have 



imagined that the sole object was to turn them 



over. This may be an advantage, since the eggs 



require damping, and, by this means, each side in 



turn is moistened by the ground. 1 No turning is 



required to ensure that the embryo which lies just 



1 E gg s that are much exposed to damp in the nest have a 

 waterproof layer. 



T 2 



