VIVARIUM EXPERIMENTS. 



METHOD. 



The vivarium jars used in the following experiments are wliat are 

 known as liquid battery jars, of a size 7% hy 8}( inches and of clear glass. 

 In the bottom sufficient earth was used to support live vegetation, usually 

 transplanted intact from the natural environment of Tettigids. Grass seeds 

 were occasionally fed or allowed to grow in the jars for the comfort of the 

 occupants. It becomes necessary sometimes to transfer species when they 

 show the slightest indications of failing vitality. Water freely supplied, of 

 course, is a necessary adjunct to their well-being. Even with due care after 

 a time, or in the course of weeks or months, the males frequently die, as 

 they are weaker than the females. A thin veiling tied on the mouth of the 

 jars is a necessary precaution to prevent their escape. Some species take 

 kindly to their new quarters in a short time, and when first introducing the 

 species in the jars, if kept in moderate darkness for a day or two they are 

 not so liable to bodily injury. A few individuals in each jar will survive 

 much longer than when overcrowding is attempted. A little numbered tag 

 is useful in marking the site where eggs are laid. 



EXPERIMENTAL OBSERVATIONS OF TETTIGIDS. 



In a jar in a window exposed to the southeast, the Tettigids are enjoy- 

 ing the sunshine. The bottom of this jar is covered with rich black loam, 

 retaining the original surface transferred from the locality where the species 

 were taken. This includes microscopic plants such as algas, lichens, and 

 mosses. The little collection of live insects recently inclosed comprises 

 one female Paratettix with long wings, two female and three male Tctti.x, 

 besides a Tetiigidt-a parvipeniiis. The Tettix are short-wing forms and 

 one of the females, found in oak woods, had a strongly carinate pronotum. 

 The other specimens were taken from a swampy locality. 



HABITS IN CONFINEMENT. 



The author saw a male Tettix approach the female Paratettix several 

 times, and she even allowed him to climb on her back, but she refused to 

 spread one of the femora from the side of the pronotum to conjugate. 



T)\e Paratettix shows more restlessness than any of the otlier Tettigids. 

 She frequently exercises her wings flying to the netting above. Tettigidea 

 parvipen}iis is a quiet, passive species in confinement and a vociferous eater. 

 The amount of excrement she passes litters up the jar in a short time. The 

 long-wing forms of all species are of course more active, owing to a desire to 

 exercise their wing power. A little fresh black muck placed in the jar at 

 intervals is selected at once by the little occupants for food , which they 

 gather around and eat with a relish. July 4, igoi. 



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