Holmes, Death-feigning in Ranatro. 215 



cessation of movement. If one approaches a group of Ranatras 

 when they are swimming about in a dish of water, it will be 

 noticed that most of the individuals cease their movements and 

 He with outstretched legs. If one remain perfectly still the 

 movements of the Ranatras are soon resumed; if now the hand is 

 passed over the dish, the Ranatras will immediately become as 

 quiet as so many sticks which they so closely resemble. If move- 

 ments near them are continued, the Ranatras soon cease to re- 

 spond so readily, and after a time they pay little or no attention 

 to what goes on around them. Specimens that have been kept 

 in the laboratory for several days are much less responsive than 

 those that have been recently brought in. 



The question naturally suggests itself, w^hether or not this state 

 of deceptive quiet has any relation to the immobile condition that 

 occurs in death feigning. So far as could be determined, the two 

 phenomena have little in common beyond a certain superficial 

 resemblance. In an insect that suddenly ceases its movements 

 in the water one may very readily move its legs about with a 

 piece of fine wire. The legs seem relaxed and oflFer almost no 

 resistance to movement. The attitude of the legs in deceptive 

 quiet is one which is quite constant and which would naturally 

 be assumed if the muscles were relaxed. If a dead and limp 

 specimen is held in the water its legs lie spread apart much as 

 they do in deceptive quiet, although not so symmetrically. These 

 facts indicate that deceptive quiet, instead of being associated 

 with the muscular rigidity that characterizes the death feint, is 

 attended by a relaxation of the muscular system. 



The subject of deceptive quiet acquires an interest because of 

 its possible relation to certain aspects of fear. What kind of 

 feelings exist in the consciousness of a Ranatra w^hen it suddenly 

 becomes quiet upon the appearance of a large object is a question 

 upon which it is perhaps not profitable to speculate. Deceptive 

 quiet may have some relation to what is commonly, though some- 

 what loosely, spoken of as the paralyzing effect of fear in higher 

 animals, but of fear in its more usual manifestations Ranatra 

 shows no sign. Species not distantly related to Ranatra, how- 

 ever, swim about upon one's approach with all the appearance 

 of violent alarm. We may say that these creatures manifest 

 fear, since they exhibit the usual outward and visible signs of 

 that state. Fear has undoubtedly arisen along many independent 



