STUDIES ON THE SERUM OF VACCINATED ANIMALS. 35 



with the spirillum of recurrent fev^r.* Mesnil noted a similar fact 

 with the Bacillus anthracis.f 



V. cholerce (culture from Constantinople). — Same result. 



B. typhosus. — There are many organisms within leucocytes of 

 which the majority have been transformed into rounded or oval 

 granules which stain shades varying from blue to pink. The change 

 is similar to that noted in the cholera vibrio. There are a few intact 

 bacteria within cells that stain with eosin. The bacilli that have 

 not been taken up by phagocytes have a normal appearance. 



B. coli. — The results are similar to those with B. typhosus. 

 The same intracellular granulation is to be noted due to the con- 

 traction of the organism. There are also some bacteria within the 

 cells that appear swollen. Stains are all the way from blue to red. 

 No change in the organism outside the cells. 



Bacillus of Hog Cholera. — The results are also similar to those 

 noted under cholera and typhoid. Within the phagocytes, in 

 addition to normal bacteria, granules stained either with blue or 

 with eosin are noted. The organisms outside leucocytes are intact. 



Bacillus of Danysz. — This organism was discovered by Danysz 

 in an epidemic among rats, and when injected into these animals 

 causes a contagious and fatal enteritis. The organism is non- 

 pathogenic for rabbits and birds, and kills only rats, mice, and field- 

 mice, so that it is actually being used in agricultural circles for the 

 purpose of destroying these harmful animals. It is a cocco-bacillus 

 that does not stain by Gram and resembles the colon bacillus in 

 general. When subjected to the leucocytes of the guinea-pig it is 

 taken up with extraordinary avidity. The phagocytes take up so 

 many bacteria that each one appears to be stuffed with them. 

 The organisms that have been taken up, when examined after the 

 usual period, are found colored violet and at times .red. 



Bacillus diphtheria;. — There is a very marked phagocytosis. 

 The shape of the organisms is not changed (at least in 4 hours), but 

 the reaction to dyes is extraordinarily modified. The majority of 

 diphtheria bacilli taken up by phagocytes are colored a deep red or 

 violet. Outside the leucocytes, on the contrary, the organism shows 



* Cantacuzene, Mode de destruction du vibrion cholerique dans l'organisme, 

 1894. 



t Mesnil, Sur le mode de resistance des vertebres inferieurs aux invasions 

 micro! >iennes. Annales de lTnstitut Pasteur, May, 1S95. 



