breathing heavily, and without making any attempt to change its position or to fly away.' ('Two of the birds,' says the report, 'were treated in this manner without effect; but the third, a siskin, fell into a sleeping condition, and remained completely immovable 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 condition, 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 experiment 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 remained rigid and motionless, as if bound, for several minutes, before the outstretched forefinger of my right hand! Yes, I could take my left hand, with which I had held the bird, and again touch the pigeon without waking it up; the animal remained in the same position while I held my outstretched finger still pointing towards the beak.' 'The lecturer,' says the report, 'demonstrated this experiment in the most successful manner with a pigeon which was brought to him.'