PHENOMENA AND CONDITIONS OF LIFE 45 



will at first make feeble defensive movements, but then lie still 

 as if paralyzed. Kircher prescribed that this experiment should 

 be conducted in the following manner : " Tie together the legs of 

 a fowl and place it on the floor, and it will at first endeavour to 

 free itself from its fetters by beating its wings and moving its 

 body. But after a few futile attempts to escape it will remain 

 quiet. Then draw on the floor a straight chalk line, com- 

 mencing from the eye of the fowl, and remove its fetters, 

 and though the fowl is no longer bound it will not run away 

 even if it be encouraged to do so." The phenomenon is caused 

 by the effects of an intense feeling of fright the fowl is in a 

 state of ' cataplexy,' as Preyer calls it. 



It has been known for 

 thousands of years that 

 the dreaded cobra, whose 

 bite invariably causes 

 death, may be paralyzed 

 by a slight pressure 

 exerted in the region of 

 the neck, and that its 

 body may then be placed 



into any desired shape. / F i G . 13. CRAYFISH IN A STATE 



The ancient miracle, per- \ OF CATAPLEXY. 



formed by Moses by 

 changing the serpent into a staff, thus probably finds a natural 

 explanation. 



Every one knows that small animals at the sight of a serpent 

 become so frightened as to remain quite motionless, thus falling 

 an easy prey. Moreover, a great fright has a paralyzing effect 

 upon a large number of animals. If one suddenly seizes a cray- 

 fish and presses it on the floor in the manner shown in the 

 illustration (fig. 13) it will remain in this unnatural position for 

 a considerable time without moving a limb. Many similar 

 cases could be quoted. 



If in the instances mentioned the animals derived no advan- 

 tage from this state of cataplexy, other animals owe to it often 

 escape from dire peril, and we are therefore justified in regarding 

 cataplexy as a form of adaptation to the conditions of life. It is 

 very common among insects and spiders, and its advantages are 



