238 INFECTIVE DISEASES. 



Klein's Micrococcus. Klein found in pneumonic sputum a 

 diplococcus which does not appear to differ from Sternberg's micro- 

 coccus. In cover-glass preparations the bacilli are surrounded with 

 a halo, but no definite capsule, as in Friedlander's coccus. They 

 appear as short rods constricted in the centre, or dumb-bell forms, 

 and forms intermediate between cocci and bacilli. In gelatine, after 

 two or three days, greyish -white spots appear, which enlarge in the 

 next two or three days into flat, translucent, greyish-white plaques, 

 with irregular serrated outline. Colonies beneath the surface are 

 spherical, and of a brownish -yellow colour. In test-tubes in the 

 depth of the gelatine a whitish-brown filament develops on incuba- 

 tion, composed of minute spherical colonies, and on the surface the 

 growth spreads out into a greyish-white film with serrated margin. 

 On the surface of obliquely solidified gelatine the growth forms a 

 thin whitish film, which enlarges in breadth with irregular outline, 

 reaching its maximum in about a fortnight. The growth on agar 

 is very similar. Broth becomes uniformly turbid in twenty-four 

 hours, then a powdery precipitate makes its appearance. On potato 

 there is a thin, moist, faintly yellowish-brown film. Cultures examined 

 in the fresh state show many rods in a resting stage, and others 

 actively motile. In addition to the dumb-bell forms there are others 

 of greater length, and in old cultures involuted and degenerated 

 forms. Spore-formation has not been observed. A broth-culture 

 inoculated into two rabbits produced a local tumour which subsided 

 in a week. Death ensued in one case in eight days, and in the 

 other in three weeks. There was purulent matter at the seat of 

 inoculation in one ; in the other, pericardial exudation and hypersemia 

 of the lungs. Broth- cultures inoculated intravenously produced no 

 effect. In guinea-pigs there was swelling at the seat of inoculation, 

 or slight indication of disease and recovery. Cultures inoculated 

 in mice produced rapid breathing, drowsiness, and death in from 

 twenty-four to ninety- six hours. The internal organs were con- 

 gested, the lungs inflamed, and the blood and organs in the inoculated 

 animals contained the diplococci in considerable numbers. 



Foa isolated a coccus which he named the Micrococcus lanceolatus 

 capsulatus. It produced in small animals either rapid septicaemia 

 and death, or local oedema and death at a later period. 



Protective Inoculation. Immunity has been produced in 

 rabbits by the intravenous injection of the virus in a diluted form. 

 Blood obtained from immunised rabbits was kept at 10 C. for twelve 

 hours, and then filtered, and animals injected with it acquired 

 immunity against virulent cultures (Emmerich). 



