344 BACTERIA. 



is sometimes found that sputum inoculated into mice or 

 ;rabbits causes their death in a comparatively short period, 

 bacterid being found in their blood ; this blood inoculated into 

 another animal. produces a similar disease, such as acute or 

 chronic abscess formation, which may be carried on from 

 generation to generation by simply inoculating a healthy 

 animal with the contents of the abscess. In these cases, 

 ihowever, the organisms that are cultivated from the blood or 

 %he pus fail to produce any symptoms at all, and it must be 

 "cpncluded (until further evidence is obtained) that the patho- 

 ,^'eihic organisms cannot live on the artificial culture media, " 

 ythose that survive on these media being non-pathogenic;' 



• There are/ howeyer, certain pathogenic organisms found in 

 ' the "mouth whicK can be readily enough cultivated, the first, 



and one of the most important of which is the micrococcus 

 :6i sputum septicaeniia, which may be grown on blood serum 



■ or agar-agar at the temperature of the body ; it grows as a 

 "transparent greyish-white gelatinous coating on the surface of 



the nutrient medium, and looks almost like a dewdrop. It 



■ is encapsuled like the pneumodoccus described by Friedlander, 

 and usually occurs in sputum i'n the form of single or paired 

 cocci ; it is found almost invariably in patients suffering 



' from pneumonia, but it also occurs frequently in the mouths 

 of healthy persons. When injected into animals, either 



• in the sputum or as a pure cultivation, death usually occurs in 

 from twenty -four to thirty-six hours ; numerous capsuled 

 ■coed are found in the blood, the spleen is enlarged and cort- 

 i tains a number of organisms ; the symptoms; in fact, are 

 'those of an acute septicaemia. It has been observed, 

 'however, that pigeons and dogs are unaffected by this dis- 

 ease, whilst rabbits and mice are almost invariably killed 



-by its inoculation. It would appear that when it makes 

 its way from the mouth to the healthy lung this organism 

 ■has little or no power of attacking the tissues, but that 

 2lf there be slight congestion or inflammation, just as in 

 'the case of inflammation of the gums around the teeth, this 

 •organism, finding its way from the mouth (where it may have 

 ■(existed for some time without giving any evidence of its 

 cpresence) into the air vesicles, is enabled to grow on the 

 -exuded fluid constituents of the blood, and to set up at once 



' Another explanation of this will be found in the chapter on 

 ' Leprosy. 



