42 Psyche [June 



and army worm blood. The blood of Melanoplus atlanis was 

 used for these four experiments and Coccobacilhis acridiorum 

 d'Herelle, pathogenic to grasshoppers, was the organism used for 

 the artificial contamination of two of the four tissue culture slides. 

 Two slides were considered as checks. They were prepared by 

 mixing a drop (Vio of a c.c.) of the grasshopper blood with a drop of 

 sterile, neutral, nutrient bouillon. The first day all of the blood 

 cells appeared perfectly normal. On the third day some showed 

 signs of disintegration, whereas others remained normal. On 

 the sixth day the cells destined to disintegrate were completely 

 disorganized. The others remained normal and showed cell 

 division with the formation of syncytial, tissue-like masses. 

 After two weeks the cells still appeared normal and the syncytia 

 had increased considerably in size. The observations were not 

 continued after two weeks. Throughout the entire period the 

 slides had remained perfectly sterile showing that all technical 

 precautions, observed during their preparation, had been adequate. 

 At no time, not even during the first day before the formation of 

 fibrin, did I observe any independent movement on the part of the 

 blood cells. They remained passive and the only visible inde- 

 pendent activity observed consisted in cell division on and after 

 the sixth day. 



The two experimental slides were prepared by mixing a drop of 

 the grasshopper blood with a platinum loop-full of a 24 hour culture 

 of the Coccohacillus acridiorum d'Herelle, a highly motile organism. 

 The slides were examined as soon as prepared. The blood cells 

 appeared to be perfectly normal and remained entirely passive. 

 The preparations were swarming with the motile bacteria and in 

 ten to twenty minutes many of the bacteria made their way into 

 the cytoplasm of the blood cells. The latter did not engulf the 

 bacteria which seemed to bore their way into the cytoplasm.* 

 On the third day the bacteria were no longer motile. They seemed 

 to be multiplying, but appeared in bunches simulating agglutina- 

 tion masses. Some of the blood cells had disintegrated; others 

 appeared perfectly normal and bacteria were no longer visible 

 within the cytoplasm. On the sixth day the bacteria seemed 

 to be in about the same condition; multiplying, bunched and 



J This may have been due to surface tension. It may be called phagocytosis if the word is 

 used in a broad sense. 



