124 THE PATHOGENIC MICROCOCCI. 



During recent years attempts to demonstrate agglutinins in 

 immune sera have met with fair results. 



Serum Treatment. Wassermami in Europe and Flexner 

 later in this country have met with good results in treating a 

 large number of cases with the blood-serum of horses im- 

 munized by repeated injections of cultures and toxic products 

 of meningococci. The serum is injected intraspinally after 

 the removal of, at least, an equal quantity of cerebrospinal 

 fluid. 



MALTA OR MEDITERRANEAN FEVER. 

 VI. Micrococcus Melitensis. 



This organism was demonstrated by Surgeon-Major Bruce, 

 of the British Army, as the cause of what is known as Malta 

 or Mediterranean fever. 



Morphology. Eound or oval cocci, 0.5 mikron in diameter, 

 occurring solitary or in pairs, in cultures occasionally forming 

 chains, and staining by the usual anilin dyes, but not by Gram's 

 method. Most observers class this organism as a bacillus. 



The micrococcus is non-motile, but Gordon claims to have 

 demonstrated the presence of from one to four flagella. 



Biologic Characters. It is aerobic. It grows very scantily 

 on gelatin at 22 C. only at the end of several weeks, and 

 does not liquefy the gelatin. It grows best in agar, stab 

 cultures showing growth only at the end of several days. 

 The colonies appear as pearly-white spots scattered around 

 the points of puncture, and as minute round white colonies 

 along the course of the needle-track, which increases in size, 

 and after some weeks a rosette-shaped growth is seen upon 

 the surface. Along the line of puncture the growth assumes 

 a yellowish-brown color. 



At 35 C. the colonies become visible only at the end of 

 seven days; at 37 C. they are seen in three or four days. 



It does not grow on potato. 



Pathogenesis. This micrococcus is not pathogenic for mice, 



fuinea-pigs, or rabbits, but subcutaneous injections in mon- 

 eys have induced fever, the animal dying in from thirteen 



