NESTS AND NEST-BUILDING IN BIRDS 



353 



of a half cup-shaped wall, and (4) finally attempting to rest in 

 the " nest " and use the breast as form long before it was physi- 

 cally possible to make the movement effective. No turning 

 movements were attempted at this early stage and there was 

 no drawing of materials to the breast, but the conduct is other- 

 wise suggestive of the robin's. There is the same scratching 

 with the legs in bringing the breast to bear, but the yielding 

 nature of the pendent mass renders such movements less 

 effective. 



At the beginning of observations on the second day (May 31), 

 at 10 A. M. little change appeared in the nest mass or "half-cup"; 

 the line of suspension had been extended about one inch and 

 a half along either twig, and though quite open on the side 

 opposite the angle, the nest-bottom had been partly framed 

 in with bast. Ten visits which immediately followed are de- 

 scribed in table VIII, and may be taken as a sample of the 

 activities at this stage. 



TABLE VII 

 Illustrating Building Activity in the Red-Eyed Vireo. First Day (May 30) 



