BACTERIA IN SURGICAL LESIONS. 451 



chains only, thirty-one groups only, and sixteen 

 both forms, or only pairs." 



Ogston was unable to discover any difference in 

 the character of the abscesses which contained 

 these different forms, and could not decide defi- 

 nitely whether they represented different species 

 or only varieties of the same species. 



To ascertain whether these micrococci possessed 

 pathogenic properties, Ogston injected pus con- 

 taining them into guinea-pigs and mice ; and, for 

 comparison, pus from cold abscesses, which con- 

 tained no micro-organisms, into other animals of 

 the same species. 



The invariable result of twenty experiments, in 

 which pus from the last-mentioned source was 

 used, was that no illness or abscess ensued. 



" But a very different effect was produced when 

 similar injections were made with pus containing micro- 

 cocci. In every instance, with the qualifications to be 

 presently made, well-marked disease was set up. Quan- 

 tities, varying from one to three minims, produced, in 

 the animals already mentioned, symptoms of blood- 

 poisoning, lasting from two to five days. . . . These 

 symptoms became less marked towards the end of the 

 first week or five days. If the animal was killed during 

 this stage, the blood in its right heart was found to con- 

 tain micrococci ; single, in pairs, and in short chains of 

 six or fewer, swimming in the serum between the cells. 

 Around the site of injection was found a patch of red 

 infiltration, varying in size, and having in its centre 

 more pus than corresponded with the quantity that had 

 been injected. The pus contained myriads of micrococci 



