144 THE LIFE OF A BIRD. 



remarkable plan of punishing the intrusion ; and 

 its actions deserve a place among the highest 

 indications of the instinct of the feathered race. 

 Mr. Nuttall appears first to have noticed this 

 remarkable part of its history. The egg, which 

 is not unfrequently deposited before that of the 

 rightful owner, is too large to be ejected from the 

 nest. A different expedient for treating it is 

 therefore had recourse to. The egg is ingeniously 

 incarcerated at the bottom of the nest, a new lining 

 being placed over it above, so that it is never 

 hatched, to become the enemy of the brood. Dr. 

 Brewer says, ts I have known four instances in 

 which a single egg had been thus buried by the 

 yellow-bird's building a second story to her nest, 

 and enclosing the intruder between them. In one 

 instance three of the yellow-poll warbler's own 

 eggs were thus covered along with that of the 

 cow-bird and another ; after an egg had been thus 

 treated, a second was laid, which was similarly 

 treated ; thus giving rise to a three-storied nest." 

 Audubon gives the following description of this 

 remarkable structure. " A nest of the usual form 

 had been constructed, of which the external dia- 

 meter was three inches. It is composed of cotton, 



