PATHOGENIC BACTERIA. 159 



Micrococcus Melitensis. (Bruce, 1887.) 



Malta fever, also known as Mediterranean fever, occurs in the 

 region from which it derives its name, but has been observed in 

 India, the Philippine Islands, and Porto Rico. Bruce culti- 

 vated a micrococcus from the spleen and proved its specificity. 



Origin. Is found most abundantly in the spleen. 



Form. Rounded or oval, 5 /u in diameter, singly, in pairs, or 

 short chains. 



Properties Non-motile, though flagella said to be present; 

 grows slowly, best at body-temperature. 



Gelatine. Not liquefied ; growth very slow. 



Bouillon. Turbid, with sediment. 



Agar. Pearly white growths. 



Potato. Slight invisible growth. 



Stained by ordinary aniline dyes. 



The disease may be produced in monkeys by even small 

 amounts of pure culture. In man a chronic, remittent febrile 

 disease is produced, with sweating and arthritis. The mortality 

 is 2 per cent. A serum reaction can be obtained and is diag- 

 nostic. 



Micro-organisms have been found by various observers in 

 meuasles, scarlatina, mumps, and whooping-cough, but their 

 specificity is still in doubt. 



PATHOGENIC PROTOZOA. 



Certain diseases are produced by animal parasites belonging 

 to the protozoa, and although not pertaining to the realm of 

 bacteriology, still the fact that they were long considered bac- 

 terial in nature and require somewhat similar methods for their 

 study renders it proper to include a brief mention of them. 



The Malarial Parasite. It has been definitely proved that 

 malarial fever is the result of the presence in the blood of a 

 protozoon which in the vast majority of cases gains entrance 

 to the body through the bite of a particular genus of mosquito 

 (Anopheles). Three varieties of the organism are recognized 

 in man, though possibly more exist, and each produces a char- 

 acteristic clinical picture. 1. The Hasmamceba vivax, the para- 

 site of tertian fever. 2. The H&mamceba malarias, the parasite 



