Immunity against pathogenic micro-organisms 161 



observer is drawn to certain macrophage leucocytes which throw out 

 one or two conical-looking processes (Figs. 2628). These pseudopodia 



FIG. 26. Leucocyte of 

 guinea-pig in the act of 

 ingesting two spirilla. 



FIG. 27. The same leuco- 

 cyte, half an hour later. 



FIG. 28. The same leuco- 

 cyte, ten minutes later 

 than Fig. 27. 



attach themselves to spirilla which exhibit very violent movements 

 as though wishing to extricate themselves from the grasp of the 

 leucocyte. Sometimes the spirillum succeeds in escaping, but usually 



FIG. 29. Leucocyte 

 of guinea-pig in 

 the act of ingest- 

 ing a very active 

 spirillum. 



FIG. 30. The same 

 leucocyte, forty 

 minutes later. 



FIG. 31. The same 

 leucocyte, half an 

 hour later than 

 Fig. 30. 



it becomes surrounded by the protoplasm and sinks more and more 

 deeply into the substance of the leucocyte. Even when almost 

 surrounded the free part of the spirillum still continues to move 

 (Figs. 29 31). These movements cease only after the complete 

 B. 11 



