60 ELIMINATION OF PATHOGENIC MICRO-ORGANISMS. 



complicated, as there are two kinds of phagocytes. The leucocytes 

 he calls " microphagi," and to the permanent tissue-cells that are 

 capable of absorbing minute solid bodies, and are provided only 

 with one large nucleus, such as the connective-tissue cells, epithelial 

 cells of the pulmonary alveoli, he applies the term u macrophagi." 

 In infectious diseases, in which the phagocytes do not protect the 

 system from progressive and rapid infection, death is inevitable. 

 In anthrax the microphagi are powerless to absorb the bacteridia. 

 The case is different, however, when, instead of a strong virus, an 

 attenuated culture is employed. Metschuikoff employed in his 

 experiments a watery solution of vesuviu, which does not color 

 living microorganisms, but stains dead ones brown. In this way 

 he saw most of the rod-shaped microorganisms, encased in the pro- 

 toplasm of the microphagi, assume a brown color, whereas the cells 

 remained unaffected and in a living state. 



Hess (" Weitere Untersuchungen zur Phagocytenlehre," Vir- 

 chow's Archiv, B. ex. p 313) has examined the influence exerted 

 by leucocytes in retarding the pathogenic action of the staphylo- 

 coccus pyogenes aureus. He injected a minute quantity of a pure 

 culture of this microbe into the substance of the cornea in rabbits. 

 The eyes were extirpated, hardened, and examined microscopically 

 "24: hours to 8 days after inoculation. During the first 24 hours the 

 cocci multiplied very rapidly at the point of infection ; 36 hours 

 after inoculation leucocytes were seen enclosing the infected area, 

 and all of them contained microbes. As the suppurative process 

 advanced the intra-cellular cocci increased in number. Gradually 

 the cocci disappeared in the cells, and after the sixth day often 

 none could be found. The free cocci in the tissues formed a very 

 narrow zone around the margins of the ulcer, while the microbe- 

 carrying leucocytes were found in the tissues at a greater distance. 

 In two cases which terminated fatally, an extensive hypopyum 

 formed and no phagocytosis had occurred, although many leuco- 

 cytes were present. In one experiment on a cat, the ulcer resulting 

 from the inoculation was very small, and in this instance phagocy- 

 tosis was more marked than in the rabbits. In the destruction of 

 the cocci in the ulcer, the cells springing from the conjunctival sac 

 played also an important part, and the secretions from the conjunc- 

 tiva contained soon after the inoculation many cells with microbes 

 in their protoplasm. Warm fomentations at first appeared to favor 

 the increase of microbes, but later, by stimulating the action of the 

 phagocytes, they retarded it. 



Christmas-Dircking-Holrnfeld (" Ueber Immunitat und Phago- 

 cytosis," Fortschritte der Medicin, No. 13, 1887) repeated the 

 experiments of Metschuikoff, and claimed that in animals immune 

 to anthrax, or rendered artificially immune, the bacillus when 



