And this is Man!
III
Fear is more manifest in birds than in any other animal. We sometimes see jugglers, as a proof of their magic power, take a little bird in their hand and lay it on its back, showing that it no longer moves, although it might easily fly away. This is an old experiment which was studied by the celebrated Jesuit Athanasius Kirchner, professor in the Roman College, who published a book in 1646 with the strange title of 'Ars magna lucis et umbræ.’ In the chapter 'De imaginatione gallinæ,’ he describes the following experiment: If the feet of a hen are tied together, and she is then laid upon the floor, she will at first try to free herself by moving her body and flapping her wings, but when she perceives that all attempts are vain, she remains quiet. If, as soon as she is motionless, a line is drawn on the floor with a piece of chalk, beginning near her eye, the bird will not try to escape even after the feet are loosed, nor even when she is coaxed to move.
Many of us, when boys, have captured a hen, screamed into her ear, and then, having put her head under her wing, have laid her breast upwards on the table, saying that she was asleep.
This trick, known I believe in many countries, may be considered as another form of the experimentum mirabile of Kirchner. No physiologist had occupied himself with this phenomenon until Czermak, in a treatise presented to the Academy of Sciences of Vienna in 1872, maintained that it arose from an hypnotic state, or momentary somnolence. But this hypothesis does not explain why the breathing is laboured, the eyes staring, why the animals are unable to move even when touched, nor why their comb and wittles are so pale, which is not the case in sleep.
Preyer was the first to declare that these effects are due to fright, and as there was no word in the German language expressing the condition of a man overcome with fright, who is incapable of speaking, moving, or thinking, he called it cataplexy.[31] From his work bearing this title I extract a few observations.
Of all mammals guinea-pigs are most susceptible to fright. Simply taking hold of them, and keeping them a moment in the hand without any pressure, is often sufficient to paralyse them with fear. Guinea-pigs may remain half an hour in this state, rabbits not more than ten minutes, while frogs will remain for hours without moving. It is impossible that this interval be spent in sleep, for the animals expel fæces and urine. Kirchner maintained the necessity of drawing a white line from the beak of the animal, so that it should imagine itself bound by this mark; but this is not true, as they remain just as motionless without the line, and cataplexy is even more easily produced when the animal sees nothing. Crabs taken out of the water allow themselves to be put into the strangest positions, and remain for a long time motionless. Preyer made similar experiments on frogs and mice.[32] Some serpents remain rigid when their head is slightly pressed, as Moses is said to have done before Pharaoh.
To produce this state a sudden, unexpected agitation is necessary; it is a matter of indifference in what way the animal is treated, as all depends on the violent fright caused. A similar condition has been observed in men struck by lightning and in animals after electrical discharges from a powerful machine. Many birds, though scarcely wounded by small shot, fall to the ground as though struck by lightning, panting, with wide-open eyes, and remaining motionless when placed on their back. This also is an instance of the cataplectic condition, for, as their wound is not mortal, nor even serious, they recover soon afterwards.
Some animals and many insects remain for a long time motionless when danger threatens. To one of these zoologists have given the name of anobium, as though it feigned death when touched. Many other coleoptera act in the same way, not even moving when they are caught, transfixed with a pin, and roasted over a flame. Preyer justly remarks that this cannot be a feint, nor an instinct which tells them to preserve the appearance of death as a means of saving their life; for it would then be incomprehensible that they should let themselves be burnt alive rather than abandon the deception.
Certainly an animal that does not move can more easily escape from an enemy. Darwin remarks that when an animal is alarmed, it stops an instant to collect its senses and discover the source of the danger, and decide whether it should escape or defend itself; but this is certainly not the origin and reason of the phenomena of cataplexy and fear, which we must consider as a serious imperfection in the animal organism.