26 QUATERCENTENARY STUDIES IN PATHOLOGY 



blood is lessened as during the months of susceptibility, the organism is 

 enabled to pass the wall of the intestine, to fructify on the peritoneal 

 liquid, and to kill the animal acutely with all the symptoms of toxic 

 poisoning. The peritoneal liquid in such instances is thick and turbid, 

 and contains the organism in abundance. 



Absence of Phagocytosis. — And here it may be mentioned that the 

 destruction of the bacillus by the blood occurs quite independently of 

 phagocytosis, for neither in the animal's blood nor in the peritoneal 

 liquid have 1 ever seen evidence of phagocytosis in this or any other 

 of these diseases. When, moreover, the organism is mixed with freshly 

 drawn sheep's blood and incubated, not a bacillus will be found to 

 have been inglobed by the phagocytes. Should there be, as there 

 sometimes is, a coccus or other impurity in the blood, the phagocytes 

 may be found to be packed with the impurity while not a single one 

 of the specific bacilli has been seized upon. Whether this depends 

 upon a powerful negative chimiotaxis existing between the specific 

 bacillus and the phagocyte or not is hard to say, but of the absence 

 of the phenomenon there cannot be a shadow of a doubt. 



Cause of the Toxic Phenomena. — It may happen, however, that in 

 other instances the blood still retains sufficient bacteriolytic properties 

 to dissolve any of the organism which gets into it, although it 

 is not sufficiently inhibitive to prevent a certain exodus of the bacillus 

 from the intestine. Those bacilli which enter the blood stream, 

 under these circumstances, are still bacteriolysed, and apparently 

 the same thing happens, but to a minor extent, within the peritoneum. 

 The blood in such animals will be found free from bacillus and the 

 peritoneal liquid may be clear and limpid, and not show any of the 

 organism until after being incubated. These cases run a chronic course, 

 and in them the nervous phenomena are most marked. The difference 

 between the acute and the chronic case seems to depend upon the 

 rapidity and volume with which the bacillus gets through the intestinal 

 wall. In the chronic case the number is evidently small, and can be 

 dealt with by the solvent action of the blood, while in the acute case the 

 number is so great that the animal dies from rapid toxic poisoning. All 

 seems to depend upon the condition of the blood. If it be in its usual 

 state of antagonism to the growth of the bacillus, such as prevails during 

 the greater part of the year, apparently the bacillus cannot leave the 



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