BLUE-GRAY GNATCATCHER. 171 



of a forest tree. It is formed of slight materials, such as the 

 scales of buds, stems and parts of fallen leaves, withered blos- 

 soms, fern down, and the silky fibres of various plants, lined 

 with a few horsehairs, and coated externally with lichens. In 

 this frail nest the Cow Troopial sometimes deposits her egg, and 

 leaves her offspring to the care of these affectionate and pigmy 

 nurses. In this case, as with the Cuckoo in the nest of the 

 Yellow Wren and that of the Red-tailed Warbler, the egg is 

 probably conveyed by the parent, and placed in this small and 

 slender cradle, which would not be able to sustain the weight 

 or receive the body of the intruder. 



Though classed with the Flycatchers by Nuttall and other writers 

 of his day, this species is now ranked as one of the highest types of 

 the Oscines, or Singing Birds, and a sub-family has been made for 

 this and the two Western forms. Mr. William Saunders finds the 

 present species fairly common near London, Ontario, but it is only 

 casual in Massachusetts, and is rarely seen north of latitude 42°. 

 It winters in the Gulf States and southward. 



