HABIT, INSTINCT, AND INTELLIGENCE. 153 



(4) The female of "pair Z)" was true to the impulse to sit, but having sat for a short 

 time in an empty box, she felt impelled to repeat the action in the same place. The i 

 ence of the eggs was of no account to her, and "seeing" them or "feeling" them did not 

 call the bird to her proper business. Even the sight of her sister on the nest, and her 

 departure, had no effect in preventing her from returning to the place she had adopted. 

 She persisted during all of the second day (and the record' will show what followed later) 

 in sitting in the empty box after having been driven away many times, and after the box 

 had been covered. 



(5) A male ring-dove mated with a common dove had been kept in a cage for 3 or 4 

 weeks. On opening the door to let them into a pen the female soon walked out; then the 

 male, anxious to follow, started to go through the door, but in passing halted and held 

 his head back with manifest fear of striking it against the wire, which was not there. 

 The head was held back and turned at right angles to the body with just the motions 

 the bird would make to avoid hitting the wire. The bird had become accustomed to 

 avoiding hitting the wire, and acted, not from a sense of sight nor from feeling, or any other 

 external stimulus, but from memory. It expected to meet the wire where it had always 

 found it before. Such action does not imply that the sense of sight is not used, but that 

 the bird did not act on a sight stimulus, since it has a contrary internal stimulus. When 

 a door is opened the bird usually behaves, in the course of a longer or shorter time, as if 

 it noticed it, but it only gradually comes to trying to pass. 



(6) The return of the parents to the nest, to call the young back for feeding after they 

 have wandered out, seems to be by force of habit rather than by instinct. From the out- 

 set the young have been fed in the nest and the parent comes to associate the nest with 

 feeding, and hence keeps up the habit some time after the young have learned to walk 

 about on the floor of the coop. 



(7) Some pigeons show a peculiar tenacity to hold their first chosen spot for roosting. 

 They insist on the identical spot, and sit in the same direction, often fighting for it as for 

 life. It is remarkable how persistently a dove seeks to gain the place it has once roosted 

 on, often taking precisely the same position with the head directed one way. If turned 

 around they immediately resume the old position. If one of a pair has had the right 

 end of the perch, and his mate happens to get this first, then both are uneasy and appear 

 to feel that something is wrong. They often work some time to exchange places, and then 

 they settle down contentedly. I have seen the birds of many caged pairs take up precisely 

 the same position and direction night after night. If a position is changed one night, 

 it is usually repeated the next. 



(8) A young homer flew from the nest out into the yard and the male parent accom- 

 panied it. It was captured and returned. The father seemed to be anxiously looking 

 for the young after I captured it and removed it from his sight. He flew back several 

 times to where he last saw the young sitting, and then went to other windows, as if search- 

 ing for it. 



(9) The young of pigeons and doves usually turn so as to sit with the head pointing 

 backward under the parent. This position is the one almost invariably taken by young 

 passengers, ring-doves, crested pigeons, and domestic doves. 



(10) A female ring-dove had a rather poor nest and one of her eggs got separated a 

 little from the other; it was lying just outside the space covered by the bird, but quite 

 near enough to be touched by the bird's feathers. She did not even try to cover it, 

 and I found it still outside on the next day. It finally got several inches away, never 

 receiving any attention. A second occurrence of the same kind w r as noted some tune 

 later. (R17, R7.) 



1 These experiments with pair D are described in detail in Chapter III, under the topic "Pairing of Two Fe- 

 males." EDITOK. 



