1918] Coccobacillus Acridiorum D'llerelle 29 



infections can be performed in this manner. Tables VIII, IX 

 and X represent another series of passages performed on another 

 species of grasshopper, Encoptolophiis sordidus. Even after 

 the 1st passage I failed to recover B. poncei. Strange as it 

 may appear, I recovered B. poncei from one animal dead in 

 the 2nd passage. 



Table XI represents thirty-five animals (If. femur-rubriim) 

 inoculated with a twenty-four hour bouillon culture of B. poncei. 

 The organism in question was recovered only three times. 



Table XII demonstrates what is meant by the rupture of 

 the gut after a foreign toxin or protein is introduced into the 

 blood. In order to see whether I was rupturing the intestines 

 myself by introducing the hypodermic needle, I injected a large 

 series of grasshoppers with a dead culture of B. poncei. After 

 three days I inoculated some bouillon tubes with some of the 

 blood taken from these animals. The tubes remained perfectly 

 sterile. 



Tables XIII and XIV represent experiments on infection 

 by feeding. Here the organisms were introduced into the 

 aUmentary tract. If B. poncei is pathogenic at all, I thought, 

 this would be the most natural method of infection. I failed, 

 however, to recover the organism either from the feces, from 

 the living infected animals, or from the alimentary tract of the 

 dead. From what did these animals die? Possibly from 

 endotoxins liberated from B. poyicei, which was destroyed within 

 the grasshopper stomach and intestines. 



The method of spraying the culture on the food foliage 

 consisted in diluting the culture one-half with sterile water and 

 spraying with a fine atomizer until the leaves were visibly wet. 



Conclusions on Experiments with B. poncei. 



I conclude from the foregoing experiments that B. ponced 

 is pathogenic to Melanoplus Jemur-rubrum and Encoptolophus 

 sordidus. In most cases, however, I failed to recover the 

 organism from the blood, the alimentary tract and from the 

 feces. My experiments lead me to believe that insects can 

 develop immunity principles which can more or less successfully 

 cope with certain foreign organisms. The following experiment 

 will further assist in substantiating this view. October 12, 1916, 

 I inoculated six female M. femur-rubrum with a twenty-four 



