i86 ROUGH WAYS MADE SMOOTH. 



in this manner without effect ; but the third, a siskin, fell 

 into a sleeping condition, and remained completely immov- 

 able on its back, until pushed with a glass tube, when it 

 awoke and flew actively around the room.') 



Also when a bird is in a sitting position, and the head 

 is pressed slightly back, the bird falls into a sleeping con- 

 dition, even though the eyes had been open. ' I have 

 often noticed/ says Czermak, ' that the birds under these 

 circumstances close their eyes for a few minutes or even a 

 quarter of an hour, and are more or less fast asleep.' 



Lastly, as to the chalk-line in Kircher's experiment. 

 Czermak found, as already said, that pigeons do not become 

 motionless, as happens to hens, if merely held firmly in the 

 hand, and their heads and necks pressed gently on the table. 

 Nor can they be hypnotised like small birds in the experi- 

 ment last mentioned. 'That is,' he says, 'I held them 

 with a thumb placed on each side of the head, which I bent 

 over a little, while the other hand held the body gently 

 pressed down upon the table; but even this treatment, 

 which has such an effect on little birds, did not seem to 

 succeed at first with the pigeons : almost always they flew 

 away as soon as I liberated them and entirely removed my 

 hands.' But he presently noticed that the short time during 

 which the pigeons remained quiet lengthened considerably 

 when the finger only of the hand which held the head was 

 removed. Removing the hand holding the body made no 

 difference, but retaining the other hand near the bird's head, 

 the hand made all the difference in the world. Pursuing 

 the line of research thus indicated, Czermak found to his 

 astonishment that the fixing of the pigeon's look on the 

 finger placed before its eyes was the secret of the matter. 

 In order to determine the question still more clearly, he 

 tried the experiment on a pigeon which he had clasped 

 firmly by the body in his left hand, but whose neck and 

 head were perfectly free. ' I held one finger of my right 

 hand steadily before the top of its beak, and what did I 

 see? The first pigeon with which I made this attempt re- 



