122 



THE POPULAR SCIENCE MONTHLY. 



CORRESPONDENCE. 



"PLATING 'POSSUM." 

 Editor Popular Science Monthly : 



IN your February issue Mr. S. F. Good- 

 rich brings up the question whether ani- 

 mals ever "play 'possum." He suggests 

 that the apparent helplessness of certain ani- 

 mals when attacked is real; that what is 

 popularly ascribed to cunning is in reality 

 due to fright — a faint, and not a feint. 



This theory is new to the great majority 

 of those who have observed the habit re- 

 ferred to ; but its newness is not of itself a 

 serious objection to it. Many familiar phe- 

 nomena have waited long before receiving 

 correct explanation. It has always been 

 taken for granted that animals passive in 

 the presence of danger were attempting de- 

 ception. Rarely has any other explanation 

 of their conduct been offered ; but it does 

 seem almost incredible that our far-away 

 kinfolk should be using that distinctively 

 human device — simulation. 



Many of these acts can be satisfactorily 

 explained on either assumption. The opos- 

 sum may at times be unable to move because 

 of his fright, or he may assume the passive- 

 ness of death as his surest hope for life. 

 Which appears the more reasonable ? 

 Granted that it is difficult for us to credit 

 the animals in question with sufficient in- 

 telligence and self-control to select deliber- 

 ately such mode of defense, does not the 

 other theory involve us in much greater 

 difficulties ? 



Do the lower animals ever feign any con- 

 dition ? If this question can be answered 

 positively, it seems to me that we shall have 

 the solution to the other problem. The cat, 

 when playing with a captured mouse, appears 

 to feign unconcern and f orgetfulness while 

 looking away from its victim, and surprise 

 on seeing it again. Probably there are very 

 few persons who have not at least once been 

 deceived by the disabled appearance of birds 

 when their nests or young were approached. 

 Very many of our birds under these circum- 

 stances act so as to draw attention to them- 

 selves, and when pursued keep just out of 

 reach, luring the pursuer to his greatest ef- 

 forts by seeming to have reached the maxi- 

 mum of their speed. Finally, the foolish 

 one, with feelings injured, gives up the chase 

 in disgust. Are the birds conscious that 

 their appearance is deceptive? Fear cer- 

 tainly did not make them really helpless. 

 If it be admitted that there is hypocrisy in 

 such cases, then it may not seem impossible 

 for even these stupid animals to feign other 

 conditions, not excepting that of death. 



If the opossum while in this passive state 

 be thrown into water, its passiveness will be 



modified somewhat, but will still be main- 

 tained. Its nose will be kept above the sur- 

 face, and it will paddle away so very gently 

 that the motion is hard to detect. If while 

 " dead " a stick be put into its open mouth, 

 it will quietly close on it with its teeth, and 

 may then be carried long distances swinging 

 from the stick, but showing no other signs 

 of consciousness; or it may be carried by 

 the tail, it doing the holding. Do these 

 facts, which none acquainted with the habits 

 of opossums will question, sustain the theory 

 of paralyzing fear ? 



The fox also appears helpless sometimes 

 when caught, and there are instances re- 

 corded of men being severely bitten because 

 of too much faith in its apparent innocence. 



The toad when captured frequently makes 

 a complete surrender, closing its eyes and 

 settling down to apparent listlessness. If 

 everything remains quiet, its eyes will soon 

 open very gradually, closing again if danger 

 be still visible ; if not, it will prepare to 

 move. If the enemy be discovered while it 

 is trying to escape, it again assumes its 

 former submissiveness. 



The actions of the spreading adder are 

 also curious. If approached, it makes a 

 hissing noise and starts forward, looking as 

 hideous as possible, as though it would 

 frighten its enemy. These motions it will 

 repeat several times if touched with the 

 finger or a stick ; but finally it seems to de- 

 spair of relief by that method, and throws 

 itself on its back and utterly refuses to make 

 further defense. On first observing this pe- 

 culiar position, I was sure the reptile was 

 dead ; but on returning a few minutes later 

 to the box in which I had it,"found it look- 

 ing all right. The same effect followed the 

 repetition of the teasing. When I turned 

 it right side up, it immediately turned back 

 again. Repeated experiment since with these 

 snakes has shown that they even resist with 

 muscular effort a change from their unnatu- 

 ral position. 



Many beetles have habits similar to those 

 of the animals named, and, like them, their 

 pretense is overdone. When the Colorado 

 beetle, or potato-bug, falls from the potato- 

 vine on being approached, it nearly always 

 comes to the ground with the feet up. 



Many other examples might be given ; 

 but the above, I think, are sufficient to show 

 that the theory that in the phenomena under 

 consideration the animals are helpless from 

 fright is untenable. In almost every case 

 the animal manifests consciousness, shows 

 itself cognizant of the situation, and betrays 

 its anxiety to escape. H. L. Roberts. 

 Lewistown, III., February 23, 1889. 



