HABIT OF THE WATER-STRIDER GERRIS REMIGES 399 



alcohol and some, in coal oil. They first approached the flies 

 carefully, then left them, but soon returned and attacked them 

 in spite of the taste or odor. Three days later these same insects 

 were fed flies which had been soaked in ammonia for twenty- . 

 four hours. The following morning they were dead. The 

 insect attacks fresh and decaying matter indiscriminately. 



Gerris remiges can live on land as well as in water. It runs 

 with a jerking motion, making from four to six jumps in succes- 

 sion and then making a short stop. Very often it turns a som- 

 mersault and continues running without interrupting its course 

 until it reaches a place of safety. There it lies quietly for from 

 fifteen to twenty-five minutes, then suddenly begins its race 

 again. The insect can right itself when placed on its back by 

 turning over longitudinally, resting its body on the head or 

 abdomen. If a water-strider is held up by some of its legs, it 

 tries to free itself by pushing the object holding it with the 

 remaining free legs, at the same time pulling the legs which are 

 being held. 



The water-strider is accustomed to cleaning itself and some 

 times is engaged in this occupation for hours. It rubs one leg 

 with another, then it rubs its proboscis and the ventral and 

 dorsal surface of the body interchangeably. Very often it rolls 

 over in the water during the cleaning process. If some foreign 

 substance, such as dust or asphalt is put on the dorsal surface 

 of the body the animal dives and rubs itself in the greatest 

 effort to get rid of the substance. If the insect is left in a weak 

 light it remains quiet excepting that it rubs its legs; if brought 

 into a strong light, it swims towards the source of light as nearly 

 as possible, and rubs its legs. 



Feigning death is a characteristic of this insect, which is 

 especially well developed in some individuals. In accomplishing 

 this feat it crosses its forelegs and becomes perfectly rigid. It 

 may be rolled on the floor, picked up and held by one leg, dashed 

 with water, exposed to considerable heat or to strong light 

 without showing any signs of life. If left alone it lies quietly 

 for ten or fifteen minutes, then gradually livens up and begins 

 to run. If touched, it again feigns death, and thus it may 

 continue for hours. The insect can be artificially made to as- 

 sume this condition by putting it on its back and holding the 

 hind legs, at the same time gently tapping it on its ventral 



