GASTRIC C/ECA OF THE HETEROPTERA. 



this organism, especially in the case of many of the common 

 gregarious, phytophagous Heteroptera, such as the chinch bug, 

 the squash bug, or Murgantia. It is a very common habit with 

 these insects, as I have frequently observed, especially when in 

 the immature condition, to sample with their beaks any drop of 

 liquid that they may find; such as drops of dew, drops of sap 

 exuding from wounds in the host plant, or even the liquid 

 excrement from other individuals. 



From these facts, and since the bacteria appeared to be limited 

 to the alimentary canal of the host, it was assumed that the 

 infection probably occurred by way of the mouth and that the 

 alimentary canal was doubtless invaded at some time during the 

 early nymphal life of the insect. 



Proceeding on this assumption, it was planned to rear the 

 insects from the egg in sterile cages in order to have material for 

 use in infection experiments with the different organisms that 

 might be isolated from the caeca. Anasa tristis was selected at 

 first for this rearing work, since the eggs of this species are very 

 easily obtained in quantities at any time during the summer, and 

 also because they are perfectly smooth and readily sterilized. 

 As it was planned at first, the rearing of these sterile bugs should 

 have been a comparatively easy matter. Since it was found that 

 this insect is able to live and develop fully as well on the squash 

 itself as upon the sap of the vine and leaves, the only essential 

 equipment for a breeding cage would have been very simple 

 indeed. The breeding cage, as I had intended to arrange it, 

 was to have been merely a rather wide-necked Ehrlenmeyer 

 flask of something like 500 c.c. capacity, plugged with cotton and 

 sterilized. Small pieces of squash, removed aseptically, were 

 then to be introduced into the flask, together with the sterilized 

 eggs of the squash bug. 



As a preliminary to this breeding work, experiments were 

 carried out to determine whether aseptic material could be 

 readily secured from the squash, and especially whether the 

 eggs of the squash bug could be sterilized effectively without 

 interfering with the subsequent development of the embryo. It 

 was found that with a little care, pieces could be removed from 

 a squash without any risk of contamination; and it was also 



