CHAPTER XII 



DEVELOPMENT AND CARE OF THE YOUNG 



I 



EGG AND CHICK 



THE nest or the spot on which the eggs are laid becomes in 

 most birds the center of the home-life, and is the focal 

 point of our interests, because it is there that the young are 

 born. We have briefly analyzed the principal terms of the 

 reproductive cycle (Chapter I.), and have seen the rise and 

 interplay of a series of commanding instincts, which develop 

 in a definite order and run a definite course, one, if unchecked, 

 leading to the next in sequence. When the young are hatched, 

 a complicated routine of nest-life is developed. The parental 

 instincts reach a climax and then, gradually yielding to im- 

 pulses of another kind, subside. 



Each term of the cycle invites us to renewed study and 

 observation in all the great families of birds, but we can men- 

 tion only a few of the interesting facts which have been gathered, 

 or were already known. 



The size, form, and color of the eggs, as well as the time 

 when they are laid, are subject to great variation, not only in 

 birds as a class, but in a lesser degree in the same species, and 

 even in the same individual. 



The ovarian tube is no respecter of particular eggs or egg- 

 fragments, but treats all alike. Double- or triple-yolk eggs are 

 occasionally seen, but still rarer cases are recorded in which a 

 normal egg of the domestic fowl or goose, with one or even two 

 yolks, was enclosed in a shell of colossal size. Again, a small egg or 



167 



