PHAGOCYTOSIS. 61 



introduced into the tissues is devoured by the leucocytes. He 

 experimented with a very virulent culture aud cultures attenuated 

 by age, or by Koch's method of attenuation. These experiments 

 were made on mice, rabbits, and young and old rats. He soon 

 found out that the results were greatly modified by the degree of 

 susceptibility of the animal to the anthrax bacillus. In animals 

 very susceptible to the disease, as in mice and rabbits, the inocula- 

 tion of a very active culture produced little or no inflammatory 

 reaction at the point of inoculation. In animals with a greater 

 degree of immunity, as young rats, the injection produced suppura- 

 tion at the point of inoculation, which assumed the character of an 

 abscess, as the susceptibility was diminished as in old rats. The 

 injection of a mitigated culture produced suppuration even in 

 rabbits. The intensity of the inflammatory reaction following the 

 inoculation with the bacilli of anthrax stood in an inverse ratio to 

 the degree of the susceptibility of the infected animal. The bacilli 

 were never found in the interior of the pus-corpuscles, and it 

 followed as a natural conclusion that death and disintegration 

 were effected by the pus serum. That the pus-corpuscles did not 

 destroy the bacilli was also proved by another experiment. A 

 pure culture of anthrax bacilli was put in hermetically-sealed glass 

 tubes containing pus, which when kept at the temperature of the 

 body killed the bacilli in from two to three days. Metschnikoif 

 asserts that the latter observation does not prove that the pus-cor- 

 puscles did not act the part of phagocytes, as under the conditions 

 described they might have retained the properties of such. 



Wehr (" Ueber den Untergang des Staphylococcus pyogenes 

 aureus in den durch ihn hervor-gerufenen Entzuudungs-processen 

 in der Lunge," Dissertation, Bonn, 1887) injected pure cultures of 

 the Staphylococcus pyogeues aureus into the trachea of rabbits and 

 favored the descent of microbes into the finer divisions of the bron- 

 chial tubes by standing the animals for some time upon the hind 

 legs. Soon after the injection he found cocci not only in the inte- 

 rior of leucocytes which had grouped around the seat of injection, 

 but also in the interior of epithelial cells. He assigns to epithelial 

 cells phagocytic action. During the first week after injection he 

 found cocci without exception in the epithelial cells. In none of 

 his experiments could the microbes be found in the blood or in any 

 of the internal organs. 



The doctrine of phagocytosis has recently received a substantial 

 support from the researches of Nuttal and Buchner ("Uber die bak- 

 terienodtende Wirkung des Zellenfreien Blutserums," Centralblatt f. 

 BaUeriologie u. Pamsitenkunde, B. v.-No. 25). These researches 

 show that not only the cellular elements of the blood are antago- 

 nistic to pathogenic bacteria, but that the serum possesses a similar 



