198 SUMMARY OF CURRENT RESEARCHES RELATING TO 



highest degree probable that B. mucosas is the exciting agent of ozama. 

 The observations and opinions of other writers on the aetiology of ozaena 

 are fully discussed by the author. 



Diagnosis of Bacterium typhi from Bacterium coli.* — J. Ram- 

 bousek, who made a comparative and critical study relative to the dis- 

 tinguishing criteria for arriving at a determinate diagnosis between 

 Bacterium typhi and B. coli, found that the most important difference 

 between these two organisms is that the latter forms gas in saccharated 

 media, while the typhoid bacillus does not. 



Antagonism of the Bacillus coli and the Bacillus typhosus.t — 

 Dr. L. Remy contests the view maintained by Wathelet and others that 

 the bacillus of typhoid is overpowered in the intestine by the coli 

 bacillus. It is true, however, that tho commensalism may materially 

 affect the characters and properties of the two organisms, the typhoid 

 losing its sensibility to agglutinins, and the coli bacterium becoming 

 unable to form gas and indol. Some coli colonies, when three or four 

 weeks old, approximate in size and appearance to the typhoid ; they are 

 distinctlv blue, while the latter are bluish-white. 



While the agglutination by strong antityphoid serum of a bacillus 

 having the characters of the typhoid may be regarded as proof of its 

 typhoid origin, the absence of agglutination would not be regarded as 

 disproof. Bacilli having typhoid characters, but which are not agglu- 

 tinated by antityphoid serum, must be regarded as typhoid if a guinea- 

 pig injected every two days with 2 ccm. of a 48 hours' culture furnishes 

 after 15 days a serum capable of agglutinating the typhoid bacillus at 

 a minimum dilution of ■£$. Some undoubted typhoid bacilli fail to be- 

 come agglutinated by the antityphoid serum : it is impossible to deter- 

 mine their typhoid nature by the foregoing or any ether known method. 



Relations of Bacillus X, Bacillus icteroides, and the Bacillus of 

 Hog-Cholera.J — W. Reed and J. Carroll, who have made a comparative 

 study of the biological characters and pathogenesis of Bacillus X, 

 (Sternberg), Bacillus icteroides (Sanarelli), and tho hog-cholera bacillus 

 (Salmon and Smith), have arrived at the following conclusions. Bacillus 

 X belongs to the colon group. B. icteroides is a member of the hog- 

 cholera group. The various channels of infection, the duration of the 

 disease, and the gross and microscopical lesions in mice, guinea-pigs, and 

 rabbits, are the same for B. icteroides and the hog-cholera bacillus. The 

 clinical symptoms and lesions observed in dogs inoculated intravenously 

 with B. icteroides are reproduced in these animals by infection with 

 the hog-cholera bacillus. B. icteroides, when fed to the domestic pig, 

 causes fatal infection, accompanied by diphtheritic, necrotic, and ulcera- 

 tive lesions in the digestive tract, such as are seen in hogs when infected 

 with the hog-cholera bacillus. 



This disease may be acquired by exposing swine in pens already 

 infected with B. icteroides, or by feeding them with the viscera of in- 

 fected pigs. Guinea-pigs may be immunised with sterilised cultures of 

 B. icteroides from a fatal dose of the hog-cholera bacillus, and vice versa. 



* Arch. f. Hygiene, xxxviii. p. 382. See Bot. Centralbl., lxxxiv. (1900) pp. 375-C. 



t Ann. Inst. Pasteur, xiv. (1900) pp. 707-22. 



% Journ. Experim. Med., v. (1900) pp. 215-70 (1 pi.). 



