The Instinct of Feigning Death 209 



is characterized by a tetanic contraction of the mus- 

 cles. The attitudes assumed by many forms, such 

 as rolling into a ball, keeping the legs and other 

 appendages drawn close to the body, or, in some 

 cases, holding them straight and rigid, are such as 

 can be maintained only at the cost of considerable 

 muscular effort. If a Ranatra is picked up by one 

 of its slender legs it may be held out horizontally 

 for a considerable time without causing the leg to 

 bend. The situation is similar to that of a man 

 seized below the knee and held out straight, face 

 upward, without causing the knee to bend. As the 

 legs of Ranatra are relatively exceedingly slender, 

 the muscular tension which the insect maintains must 

 be intense. Similar muscular rigidity is shown in 

 the walking-stick Carausius studied by Schmidt. 

 Specimens supported by the tip of the abdomen and 

 the ends of the outstretched fore legs would lie 

 straight as a stick for hours. 



Death feigning is markedly influenced by external 

 conditions such as light, contact, moisture and espe- 

 cially temperature. In experimenting with amphi- 

 pods I have found that when the temperature is 

 lowered the death feint persists for a considerably 

 longer time. The same is strikingly true of the 

 death feint of Ranatra. At temperatures higher than 

 the normal the Severins found that the duration of 

 the death feint in the water bugs Nepa and Belos- 

 toma was greatly decreased. A sudden transition 

 from a warm to a cold temperature, however, was 



