The Bird in the Egg 479 



ably functional. In an embryo chick of even the third 

 day this organ is remarkably prominent; but although 

 traces of it always remain, yet it fades away to a vestige. 



Look with a hand-lens at the head of a polywog, and 

 see the whitish dot between the eyes; or when you touch 



Fig. 370. — Forty-day embryo Ostrich, showing position in the shell. 



the ''soft spot" on the head of a human baby, let it recall 

 the strange third eye which is its cause. 



And so we might continue to tell of the wonder of 

 embryo life: how up to the sixth day the little being 

 might be mistaken for the embrj^o of a reptile or a mammal, 

 but from this day onward the bird characteristics become 

 more and more noticeable. On the ninth day feathers 



