PATHOGENIC BACTERIA. 255 



G. and F. Klemperer claim to have obtained toxins from 

 cultures of the pneumococcus, and to have established im- 

 munity in animals with the development in the blood of 

 antitoxic substances. Similar attempts have been made by 

 Washbourn and others, but the interpretation of them at 

 the present time is not clear. An agglutination reaction 

 has been described as occurring with the pneumococcus, but 

 it does not yet appear to have any practical value in diag- 

 nosis. 



Organisms related to the pneumococcus have been de- 

 scribed under the names of pseudopneumococcus 1 and strep- 

 tococcus mucosus. 2 



The organism named by Rosenbach, micrococcus pyo- 

 gcncs tennis, is probably only a variety of the pneumococcus. 



Micrococcus melitensis. A micrococcus found by Bruce 

 in cases of Malta fever. It is a round or slightly oval 

 organism, about .5 IJL in diameter, occurring singly, in pairs 

 or in short chains. It is usually said to be non-motile, 

 though flagella have been described. It is stained by ordi- 

 nary aniline dyes, but not by Gram's method. It grows 

 slowly, even in the incubator, and more slowly at ordinary 

 temperatures. In gelatin the growth is feeble; there is no 

 liquefaction. On agar pearly white growths appear after 

 three or four days. Bouillon becomes turbid, with a sedi- 

 ment later. On potato there may be slight invisible growth. 



Malta fever occurs chiefly about the Mediterranean. It 

 has been observed in India, in the Philippine Islands and in 

 Porto Rico. 



It is a chronic febrile disease, accompanied by pains in the 

 joints and perspiration, and not very fatal. At autopsies 

 the organisms may best be recovered from the enlarged 

 spleen. Accidental infection in man has occurred from pure 



1 Richardson, Journal Boston Society of Medical Sciences, Vol. V., 

 1901. 



2 Howard, Journal Medical Research, Vol. VI., 1901. 



