252 BACTERIOLOGY 



in the intestinal tract. They are motile bacilli which do 

 not liquefy gelatine by their growth, possess the peculiarity 

 of offering resistance to moderately concentrated acids, and 

 hence are able to pass through the stomach without injury 

 to their vitality. 



Bacillus dysenteriae. Chantemesse andWidal discovered 

 short rods with rounded angles and but scanty power of 

 movement in the contents and walls of the intestines, as 

 well as in the spleen and abdominal glands, in cases of 

 dysentery. They take up the aniline colours badly, and 

 do not liquefy gelatine. On the plate there develop at first 

 small white specks, which assume a yellow colour and unite 

 with the neighbouring islets ; but in some days the yellow 

 colour vanishes, and the colonies become white and granular. 

 A dry yellow membrane develops on potatoes. 1 



Bacillus of fowl cholera. Poultry typhoid or fowl cholera 

 is an epidemic disease accompanied by diarrhoea, often 

 occurring amongst poultry, and which Perroncito first in- 

 investigated more thoroughly. Pasteur describes it as 

 * cholera des ponies,' and more recently Marchiafava, Celli, 

 and Kitt have been occupied in bacteriological research 

 concerning it. 



In the blood, in the capillaries of all the various organs, 

 particularly the spleen and liver, and in especial abundance 

 in the intestinal contents, there are found short plump rods 

 which are somewhat constricted in the centre. A typical 

 attack of the disease can be caused in hens by inoculation 

 with these or by feeding the fowl with them, and other 

 birds also, such as geese and pigeons, are very susceptible 

 of infection, as are, moreover, mice and rabbits. Guinea- 

 pigs, however, prove refractory. The growth of the bacilli 



1 [Many cases of dysentery are, however, believed to be due to the action 

 of a protozoon, named by Losch Amceba coli, by Councilman and Lafleur 

 Amceba dysenteries, for an account of which the reader is referred to the 

 Appendix.] TB. 



