SCHIZOPHYTA SCHIZOMYCETES 169 



the heart; capsule of the spleen thickened and contracted. Small intestines with 

 a local superficial or completed necrosis of the glandular areas. The blood 

 examination shows polycythemia, leucocytosis, and in advanced stages, general 

 poikilocytosis. True toxins not produced. 



Immunity. Filtrates seem to have some immunizing power, probably either 

 bactericidal or opsonic. The serum of immune animals has little or no im- 

 munizing power. Sterilized cultures and filtrates heated for thirty minutes at 

 60 C. lose their immunizing power. 



Miccrococcus meningitidis, (Diplococcus intracellulus meningitidis, Weichsel- 



baum) 



Name of. disease. Epidemic cerebro-spinal meningitis. 



Animals infected naturally. Man. 



Animals susceptible. None, except when injected into a cavity in large 

 quantities. Subdural inoculations in most cases produce a meningitis which, 

 however, does not agree with that produced in man. 



Pathogenesis. Severe inflammation of the meninges of both brain and 

 spinal column characterized by the production of considerable quantities of pus. 

 The lumbar puncture and a microscopic examination of the pus will show the 

 organisms present in large numbers. Probably the organisms sometimes reach 

 the blood stream, and secondary infections are produced in various parts of 

 the body by metastisis. It is very probable that the organism is present in 

 acute rhinitis, and that the infection of the brain and spinal cord is secondary. 



Poisonous properties. Lipierre extracted what he called a toxin with 

 glycerine, from old culture. 



Immunity. Second attacks of the disease are very rare. Lipierre claims 

 to have immunized animals with the toxin and with cultures produced 

 a preventive curative serum from immunized animals. Davis states that there 

 is developed a bactericidal property in the serum, and also agglutinins. 



Micrococcus lanceolatus, Fraenkel 



Disease produced. Acute infectious pneumonia. 



Animals infected naturally. Man (and domestic animals). 



Animals susceptible. Rabbit, guinea-pig, dog, and mouse. 



Animals immune. Chicken and pigeon. 



Pathogenesis. The lungs are most frequently the seat of infection. The 

 infected portion passing through several stages; first, that of congestion, in 

 which the air cells become filled with blood serum and red corpuscles, the 

 former coagulates, the tissues become liver-like in consistency ; this is followed 

 by a marked invasion of leucocytes ; the contents of the air cells soften and 

 are absorbed and discharged. In most cases of the disease, blood infection prob- 

 ably occurs, consequently, in many cases, infection of various other organs. 

 Pleuritis is most common, then pericarditis, and even generalized peritonitis, 

 endocarditis, arthritis, meningitis, otitis media, conjunctivitis, osteomyelitis, and 

 degenerations in various internal organs, particularly the kidneys and liver. 



Poisonous properties. Poisonous substances are produced in greater or 

 smaller quantities in culture media, but no true soluble toxin. Presumably, 

 there is present an endotoxin. The pneumotoxin seems to be toxic toward all 

 the organs of the body. 



Immunity. Immunity is probably due largely to phagocytosis, and it is 



