556 



DESCRIPTION OF SPECIES. 



diam., singly, in pairs, and in 

 masses. They can be cultivated 

 at 37 C. 



The colonies on agar are milk- 

 white and prominent. Later, off- 

 shoots occur from the margin, 

 producing a resetted appearance. 



Inoculated in the depth of 

 gelatine the cocci form clubbed or 

 stalactitic out-growths from the 

 filament which develops in the 

 track of the needle. 



On the surface of agar a creamy 

 layer is formed with similar off- 

 shoots. 



Injected into the lungs of guinea- 

 pigs they are said to produce 

 broncho-pneumonia. 



They were obtained from the 

 bullae in acute pemphigus. 



Micrococcus in pneumonia 

 (Manfredi). Oval cocci -6 to 1 /z 

 in width, 1 to 1*5 p. in length, singly, 

 in pairs, and short chains. 



Colonies on gelatine are circular, 

 whitish, and later spread out and 

 become bluish by transmitted light, 

 and of a pearly lustre by reflected 

 light. 



Inoculated in the depth of gela- 

 tine there is a limited growth along 

 the track of the needle. 



On blood serum they form a 

 shining, granular, faintly greenish- 

 yellow layer. 



They also can be cultivated on 

 potato and in broth. 



They are pathogenic in dogs, 

 rabbits, guinea-pigs, mice and birds. 

 Birds die in a few days ; mammals 

 in from one to three weeks. After 

 death new growths composed of 

 granulation tissue are found in the 

 internal organs, varying in size 

 from a millet seed to a pea. They 

 were obtained from the sputum of 

 pneumonia complicating measles. 



Micrococcus in progressive 

 abscess formation in rabbits 

 (Koch). Cocci only about '15 ju, in 

 diam., principally in thick zoogloea. 

 The disease was induced by the in- 

 jection into rabbits of decomposing 

 blood. At the place of injection a 

 spreading abscess formed, which was 

 fatal to the animal in about twelve 

 days. No bacteria were observed 



in the blood, but in the walls of the 

 abscess thick masses of cocci were 

 found. The pus is infectious, 

 causing the same disease in healthy 

 rabbits. 



Micrococcus in pyaemia in 

 rabbits (Koch). Round cocci and 

 diplococci -25 p in diam. 



The disease was produced by the 

 subcutaneous injection, in a rabbit, 

 of distilled water in which the skin 

 of a mouse had been macerated. 

 At the autopsy there were found 

 great infiltration around the site of 

 injection, peritonitis, and accumu- 

 lations in the liver and lungs ; in 

 short, the appearances of pyaemia. 



FIG. 220. MICROCOCCUS IN PY.EMIA 

 IN RABBITS : VESSEL FKOM THE 

 CORTEX OF THE KIDNEY x 700. 

 a, Nuclei of the vascular wall ; 

 f, , Masses of raicrococci adherent 

 to the wall and enclosing blood- 

 corpuscles (Koch). 



In the capillaries of the organs 

 examined, masses of cocci were 

 observed enclosing blood-corpuscles. 

 Fresh inoculations in rabbits with 

 exudation-fluid, or blood from the 

 heart, reproduced the same disease. 

 Micrococcus in septicaemia in 

 rabbits. Ellipsoidal cocci '8 to 1 

 p. in largest diam. The disease 

 was produced by the injection of 

 putrid meat infusion. After death 

 slight oedema was noted at the site 

 of injection, slight extravasation of 

 blood, and great enlargement of 

 the spleen. No emboli or peri- 

 tonitis resulted. Masses of cocci 

 were found in the capillaries of 



