288 ORGANISMS RESEMBLING BACILLUS TYPHOSUS. 



Tliis organism has been designated as the paratyphoid bacil- 

 lus, and is accepted as the specific cause of paratyphoid fever. 



Its morphology is exactly like that of the typhoid bacillus. 



Its growth on gelatin, agar, and in bouillon is also the 

 same as that of the typhoid cultures. Indol-production is 

 either absent or very slight. Litmus-milk remains unchanged. 

 According to some authorities, there is a terminal alkalinity 

 in from one to two weeks. The organism does not aggluti- 

 nate with typhoid blood, but does with the blood of persons 

 suffering with paratyphoid fever. 



The bacillus is a very short rod with rounded ends, and has 

 from ten to twelve terminal and lateral flagella. It is actively 

 motile. It is also identical with Bacillus psittacosis, which 

 was discovered and isolated by Nocard. 



During an epidemic of infectious pneumonia Widal found 

 the paratyphoid bacillus in an abscess in the neighborhood 

 of the thyroid gland. It has also been called the paracolon 

 bacillus and bacillus 0. 



Further investigations are necessary in order to give us a 

 more complete history of this organism. 



