82 MICRO-ORGANISMS AND DISEASE. [CHAP. 



13. Koch 1 described various kinds of micrococci inti- 

 mately connected with certain destructive (pyaemic) processes 

 in mice and rabbits, (a) Micrococcus of progressive necrosis 

 in mice. Injecting into the ear of mice white mice, or 

 better, field mice putrid fluids, he observed a necrosis of 

 the tissues of the ear (skin, cartilage) starting from the point 

 of inoculation and gradually spreading on to the surrounding 

 parts and killing the animal in about three days. As far as 

 the necrosis reaches, the tissue is crowded with micrococci, 

 chiefly in the form of chains and zooglcea. The individual 

 cells are spherical, of about 0-0005 mm. in diameter. I 

 may mention that I have found a somewhat different micro- 

 coccus virulently active on mice. I have inoculated a 

 number of white mice subcutaneously in the tail with a 

 small micrococcus cultivated through several generations, 

 and apparently derived from an artificial cultivation in pork 

 broth, but due to accidental contamination. These micro- 

 cocci, after having been cultivated in pork broth through 

 several generations, were used in infinitesimal doses for the 

 inoculation of the above mice. In two instances I have 

 seen that the inoculation was followed after two or three 

 days by purulent inflammation at the seat of inoculation, 

 but apparently not spreading beyond it. But as time went 

 on inflammation and abscess in the lungs set in and the 

 animals died after about a week. On making longitudinal 

 sections through the tail, it was found that in most of the 

 lymph-spaces and lymph-vessels of all parts of the cutis and 

 subcutaneous tissue, far away from the seat of inflammation, 

 there were densely crowded masses of the same minute 

 micrococci as were used for inoculation. And these crowds 

 of micrococci could be traced to the seat of inflammation, 



1 Untersuchungen iiber die Aetiologie d, WundinJections-Krankheiten, 

 Leipzig, 1878. 



