574: 



THE POPULAR SCIENCE MONTHLY.— SUPPLEMENT. 



tory effect on the will, and eventually a state 

 of stupor. It may, I think, still be questioned 

 whether this theory is of very much value, for, 

 even granting that " deathly terror " is always 

 present — which it certainly need not be when the 

 subject of the experiment is a human being — we 

 are not acquainted with any other facts which 

 would .lead us to connect the subsequent state of 

 motionless stupor with the preceding state of 

 active fear. 1 But, passing on to the facts, we 

 soon find that an important exception must be 

 taken to the above statement as to the condi- 

 tions under which hypnotism occurs, for vari- 

 ous experiments proved that "sudden, strong, 

 unexpected, and unusual stimulation " of any 

 of those " centripetal nerves " which minister to 

 the special senses, so far from inducing a state of 

 hypnotism, instantly aroused an animal which had 

 been previously thrown into that state. So that, 

 in point of fact, as we are afterward told, we 

 may more correctly state the conditions which 

 produce kataplexy in animals, by substituting for 

 the words " centripetal nerves " in the above- 

 quoted proposition the words " nerves of tactile 

 sensation." But here I may observe that, so far 

 as the experiments go, there is nothing to prove 

 that special stimulation of even the cutaneous 

 nerves is necessary (indeed, thermal and chemical 

 stimulation of the skin was specially tried and 

 produced no results) ; and therefore, it seems to 

 me, the possibility is not excluded that the spe- 

 cial stimulus in question may really have refer- 

 ence only to the " muscular sense." At any rate, 

 all these experiments go to prove that kataplexy 

 can only be produced in animals, either by sus- 

 pending them in the air, or by forcibly holding 

 them in some unusual position. Most animals re- 

 cover their normal state after a few minutes, but 

 frogs when suspended in the air will continue kata- 

 plectic until they die. Horses become kataplec- 

 tic while they are being swung from wharves to 

 ships, as shown by the fact that they remain pas- 

 sive so long as they are suspended in the air, but 



1 Indeed, a very remarkable experiment which is 

 detailed further on would seem to show that even in 

 the case of animals the state of fear need have noth- 

 ing to do with inaugurating the state of kataplexy. 

 The experiment in question consisted in suddenly de- 

 capitating a fowl, and while the reflex convulsions were 

 still in progress, holding the mutilated body firmly on 

 its back. The convulsions forthwith ceased, and the 

 headless animal became for a time kataplectic. Un- 

 less, therefore, we suppose that the spinal cord is ca- 

 pable of suffering fear, and that it is more alarmed by 

 being held firmly down than by being severed from the 

 brain, we must conclude that a state of fear is no es- 

 sential antecedent to that of hypnotism. 



again begin to struggle so soon as their feet touch 

 the deck. Preyer has succeeded in rendering 

 kataplectic various species of toads, newts, frogs, 

 ducks, poultry, peafowl, partridges, sparrows, 

 mice, Guinea-pigs, rabbits, etc. ; but has uniform- 

 ly failed in the case of many other animals. On 

 the whole he concludes that while among sundry 

 species of reptiles, 1 batrachians, birds, rodents, 

 and ruminants, the phenomena of kataplexy may 

 be more or less easily produced, such is not the 

 case with fish and the more intelligent mammals. 

 Nevertheless in another part of his memoir he at- 

 tributes to a state of partial kataplexy the period 

 of motionless delay which is observable in chil- 

 dren after they unexpectedly fall and before they 

 begin to cry. He also states, on the authority of 

 Dr. Genzmer, that a squalling child (not a young 

 baby) may often be quieted by laying it upon its 

 stomach, or by gently pressing its face with the 

 hand — care being taken in neither case to inter- 

 fere with the breathing. 



Our author further maintains that the so- 

 called " shamming-dead " of certain species of 

 Articulata, when in the presence of danger, i8 

 probably to be attributed to kataplexy. But 

 here, I think, it is difficult to agree with him. 

 That the action in question is not a properly so- 

 called intelligent one, no competent person at the 

 present day is likely to dispute ; but, for my own 

 part, I cannot see any evidence to show that it is 

 not of the nature of an instinctive action,' which 

 has been developed in the way to which Preyer 

 alludes. It being for the benefit of some animals 

 that they should remain motionless, and thus be 

 comparatively inconspicuous in the presence of 

 danger, those individuals which endeavored to 

 escape would be destroyed, while those which 

 ceased to move would survive. Natural selection 

 would, therefore, soon fix the artifice of " sham- 

 ming-dead" as an inherited instinct. To this 

 view Preyer objects that, if we accept it, the ori- 

 gin of the instinct is difficult to explain ; while, 

 on the supposition of the action not being instinc- 

 tive, but purely kataplectic, there is no difficulty 

 to surmount. But to this it may be answered 



1 Preyer does not appear to have himself expeii- 

 mented on any species of reptile, but in another part 

 of his monograph refers in this connection to a very 

 old authority, viz., Moses, whose power of causing 

 serpents to appear like rods he supposes to have been 

 probably due to the sagacious Israelite having known 

 something about the phenomena of kataplexy. But 

 considering the number, variety, and general quality, 

 of the experiments which Moses is said to have per- 

 formed, it would surely be desirable to repeat the one 

 In question before accepting the result as a fact of 

 modern physiology. 



