58 ELIMINATION OF PATHOGENIC MICKO -ORGAN ISMS. 



aggregation of leucocytes around them occurred in the vessels and 

 tissues of the liver, and multiplication at once took place, and 

 after mural implantation of the microbes had taken place perfo- 

 ration of the vessel wall was effected by means of ray-like pro- 

 jections which developed from the microbes, and which were seen 

 to insinuate themselves between the cells. If the animal survived 

 the injection for a few days the rays became narrower and the 

 granular detritus of the microbe was removed by giant cells. In 

 studying the fate of the same microbes in the lung, the injections 

 were made either into a vein, the trachea, or directly into the 

 parenchyma. The microbes surrounded by leucocytes were seen 

 not only in the vessels but also in the alveoli. Limitation of the 

 infection and the final destruction of the microbes were here also 

 accomplished by the leucocytes and giant cells. Injection of 

 larger quantities was likewise followed by rapid permeation of the 

 vessel wall by the microbes and their early appearance in the 

 para vascular tissues. In the kidneys the growth of the microbe 

 was more rapid than in the liver and lung, the rays and filiform 

 projections formed earlier and developed to an unusual extent. 

 The accumulation of leucocytes, on the other hand, was retarded 

 and less marked, so that the microbes were only surrounded by 

 them after the thread-like projections had formed. The leucocytes 

 containing spores were not only found in the interstitial tissue, but 

 also in the tubuli uriniferi. The same microbes injected into the 

 anterior chamber of the eye produced upon the iris a thin layer of 

 fibrin, in which the leucocytes gathered around the microbes in the 

 form of minute nodules and the microbes were soon lost in their 

 interior. Only a slight increase of growth was observed in this 

 locality. The fixed cells of the iris take no part in the formation 

 of the nodules, and the work of destruction of the microbes is 

 accomplished exclusively by the leucocytes. Culture experiments 

 with small particles of organs containing the microbe showed that 

 their power to infect is sometimes lost after 24 hours and always 

 after 8 to 14 days. The retardation and arrest of germ-growth by 

 the leucocytes and giant cells are first effected mechanically, but to 

 a greater extent by the abstraction of oxygen. It is also possible 

 that the diffusion of the ptomaines of the microbes is also limited 

 by the grouping of cells around centres of infection. He does not 

 believe that the leucocytes digest the microbes, as was claimed by 

 Metschnikoff. Fibrin-production could be detected by Weigert's 

 method around the periphery of the nodules. Experiments with 

 aspergillus fumigatus yielded the same results. From his own 

 work Ribbert has come to the conclusion that retardation of germ- 

 growth by leucocytes in infectious with schizomycetes is an estab- 

 lished fact in pathology. The retarding influence of the organism 



