448 M. ARMAND EUFFER. 



these may be met with even in the clot obstructing the vessel. 

 In general miliary tuberculosis^ moreover, tubercular granula- 

 tions of the intima of pulmonary veins, of the right endo- 

 cardium, or inferior vena cava, are generally found. In patients 

 suffering from miliary tuberculosis^ bacilli have been met with 

 post mortem in the clots of large vessels. In experiments 

 in which the Bacillus pyocyaneus had been injected into 

 the veins, it was not unfrequently found that the blood con- 

 tained no micro-organisms," when the liver, kidneys, lungs, 

 and even urine, were swarming with them. The blood, there- 

 fore, is not their usual habitat ; but micro-organisms, like 

 inert powders, injected into the blood, are arrested wherever 

 the circulation is slowed by any cause ; that is, in the liver, 

 spleen, kidney, marrow of bone, lymphatic glands, &c. When 

 injected in large quantities, the bacilli may produce lesions 

 simply by their numbers. Thus most beautiful and typical 

 infarcts can be produced by injecting large quantities of a 

 culture of Bacillus pyocyaneus into an animal which has 

 been rendered artificially immune.'^ One thing is certain, 

 namely, that the activity of the lymphoid cells contained in 

 the blood and other tissues varies exceedingly, according as 

 the animal possesses some degree of immunity or not. Thus, 

 according to Metschnikotf, when virulent anthrax is injected 

 into a rabbit, the bacilli in the blood are extremely numerous, 

 and lie free in the fluid. The same observer rendered animals 

 immune against anthrax by Pasteur's method ; he then inocu- 

 lated virulent anthrax, and examined the blood at varying 

 intervals after the inoculation. Sixteen hours after the inocu- 

 lation some bacilli were still free in the fluid, while many were 

 contained in white corpuscles. Twenty-two hours after the 

 inoculation all the bacilli were contained in lymphoid cells; or 

 if by any chance a number of them were found floating free 

 in the liquid, they were surrounded by a mass of white cor- 

 puscles. Three days afterwards all the bacilli had disappeared. 



1 Weigert, " Zur Lelire vou der Tuberculosc," ' Vircliow's Arcliiv,' 1882. 



^ Cbarrin and Armaud Ruffer, loc. cit. 



3 Cliarrin and Armand Rufifer, C. R., ' De la Societe de I'Anatomie,' 1889. 



