568 PATHOGENIC SPIRILLA. 



typhoid fever. But as the discharges had been mixed with Berlin hydrant 

 water, Ivanoff admits the possibility that his vibrio came from this water. 

 It closely resembles the cholera vibrio, but is distinguished by its colonies in 

 gelatin plates, which, at the end of twenty -four to thirty-six hours, in place 

 of the usual coarse granulation of cholera colonies shows a distinct formation 

 of filaments. Morphologically the vibrio is distinguished by a decided ten- 

 dency to preserve the spiral form, and especially by its size. Celli and San- 

 tori (1893) describe a Vibrio romanus, which they isolated from twelve 

 undoubted cases of cholera. This does not give the indol reaction, is not 

 pathogenic for animals, and does not grow in bouillon or agar at 37 C. 

 This is considered by the authors named an atypical variety of the cholera 

 vibrio, especially as the distinguishing characters did not prove to be perma- 

 nent. After eight months' cultivation the cultures gave the indol reaction, but 

 the pathogenic power was still almost absent. Recently Chantemesse (1894) 

 has described a vibrio which he found in the spring of 1894 during the chol- 

 era epidemic at Lisbon. This differed in many particulars from the genuine 

 cholera vibrio, resembling more closely the vibrio of Finkler-Prior. As in 

 the Lisbon epidemic, with a large number taken sick, only one death occurred, 

 and in view of the results of the bacteriological examination, Chantemesse 

 supposes this to have been an epidemic of cholera nostras. Finally, Pfuhl 

 (1894) found a vibrio in the north harbor of Berlin which from its growth in 

 gelatin and pathogenesis for pigeons he believes to be identical with Vibrio 

 Metschnikovi." 



To the list of vibrios above referred to as resembling more or less 

 closely the cholera spirillum we must add those described by Cun- 

 ningham (1894) and obtained by him from the discharges of cholera 

 patients. He has described " thirteen distinct forms obtained from 

 cases of cholera and one of non-choleraic origin." 



Pfeiffer and Issaeff (1894), in a recent publication, report that they 

 have found a sensitive test for the differentiation of these vibrios in 

 the specific character of cholera immunity. They found that guinea- 

 pigs which were immunized against cholera infection have a lasting 

 immunity, and that the serum of such immunized animals has a 

 specific action in protecting against infection by genuine cholera vib- 

 rios only, while for other species it has no action different from that 

 of the blood serum of normal animals. In all cases where the cholera 

 serum acted specifically the vibrios were promptly destroyed, while 

 in cases where this specific action was absent the injected vibrios 

 multiplied rapidly and caused the death of the animal. By means of 

 this method the vibrios isolated from water the phosphorescent 

 vibrios of Dunbar, Vibrio Danubicus, Cholera Massanah are shown 

 to be distinct species, while the vibrio of Ivanoff behaves like the 

 genuine cholera vibrio. In a subsequent paper Pfeiffer reports the 

 interesting fact that a trace of highly active cholera serum, added to 

 a culture of the cholera spirillum, when injected into the peritoneal 

 cavity of a guinea-pig, within a surprisingly brief time causes the 

 destruction of the cholera vibrios ; whereas no such effect is produced 

 upon other species. A similar destruction occurs when cholera vib- 

 rios are injected into the abdominal cavity of immunized guinea- 



