CHAPTER XIII. 



THE SWAMP, THE yiELn, AMD THE LAKE. 



IN all the domain oi: nature there is nothing which closely 

 resembles the nidification of birds. Certain reptiles lay- 

 eggs, but, properly speaking, make no nest; nor are their eggs, 

 which differ very materially from those of birds, incubated 

 by the warmth of their bodies. Every animal comes from 

 an egg, but in the case of mammalia, the young are brought 

 forth alive, and nourished by the milk of the female parent. 

 In the case of a bird, whether moving in the air or on the 

 water, lightness is a prime necessity. Hence, in bringing 

 forth their numerous progeny, they do not perfor;n the 

 office "of gestation; but the nest, and the external warmth of 

 the body, so well secured by the plumage, serve the purpose 

 of the uterine organs in the mammalia. Wonderful indeed is 

 chat internal impulse of instinct, by which the bird is in- 

 duced to make a nest, and by which it is guided in the loca- 

 tion and manner of constructing the same. How came that 

 mother-bird to know she needed a nest ? Who instructed 

 her t& adapt it to its peculiar purpose ? What strange power 

 keeps her on the nest till the young are brought forth ? 



For the most part, the different species of birds have cer- 

 tain well-defined plans for building their nests, as well as 

 certain places for locating them. The nest is placed on the 

 TiVibs of a tree or bush, in a natural or prepared cavity, in 

 an excavation of the earth, in some cemented structure, or, 



