194 PHAGOCYTOSIS 



through the walls of the vessels. Inflammatory transudates which 

 contain but few leukocytes are the exceptions. They occur only when 

 the injury is so slight that great activity is not needed or at the other 

 extreme when it is so great or the infection is so virulent that repair 

 and resistance are impossible. The mononuclear cells, the macro- 

 phages, may become fixed connective tissue and form scar-tissue. The 

 polynuclear cells, the microphages, do not serve this purpose. 



There are inflammations which are due to soluble irritants with- 

 out cellular elements. In these instances the phagocytes assemble and 

 feed on the fluid. Strictly speaking, there are probably but few 

 wounds absolutely free from bacteria, but when these are few in 

 number and non-virulent, they are soon destroyed by the phagocytes 

 and healing by first intention results. 



Fehleisen has studied phagocytosis in erysipelas. In the initial 

 stage the streptococci are, for the most part, free ; in the second, many 

 are included in phagocytes; in gangrenous areas there are but few 

 leukocytes and these show degenerative changes ; in healed areas there 

 are but few free cocci, many in leukocytes, also many macrophages. 

 Beyond the inflammatory area the cocci are free; on the edge many 

 cocci are included in phagocytes ; in the third zone the cocci are want- 

 ing and there is marked small-cell infiltration. In pneumonia the 

 favorable progress of the disease is indicated by an increase in the 

 sputum of phagocytes containing pneumococci. Immediately after a 

 slight leakage from a diseased appendix all the bacteria are free, with 

 time more and more are found in leukocytes, and in case of recovery, 

 all are disposed of in this way. 



Phagocytosis is in evidence in certain systemic infections, for 

 instance, relapsing fever. This has been studied in apes. The first 

 febrile stage lasts a few days and generally ends in permanent recov- 

 ery. Several apes were killed at different hours in the febrile stage. 

 Before the fever, the spirilla may be abundant in the blood, but with 

 the rise in temperature they can no longer be detected in the peripheral 

 circulation. At the crisis, the polynuclear cells of the spleen are filled 

 with the spirilla, some of which seem quite normal while others show 

 degenerative changes. A fresh ape inoculated with these cells develops 

 the disease, showing that at least some of the included spirilla are still 

 alive and virulent. An examination of the spleen after recovery shows 



