51 



as the lack of fermentation ol the disaccharide lactose, the 

 trisaccharide raffinose, the polysaccharide inulin, the alcohol 

 mannile and the glucosides salicin and arbutin, are common 

 to all Pfeiffer's bacilli; while the action upon the disaccharides 

 mallose and saccharose, and the polysaccharide dextrin, can 

 be utilized to distinguish the individual strains of the Pfeiffer's 

 bacillus group. 



Serological Reactions. 



Before the last pandemic there was very little information 

 about the serological reactions of Pfeiffer's bacillus. 



The first contributions date from 1903 when Cantani (3) showed 

 that Pfeiffer's bacillus could induce the production of agglutinins 

 in man as well as in animals immunised with the microbe, and 

 Vagedes found the serum of 8 out of 27 influenza patients to 

 be slightly agglutinating. 



Later Wollstein (1,2) discovered that in whooping-cough and 

 influenza. Pfeiffer's bacilli cultivated from the patients were aggluti- 

 nated by the same patients' sera. This was especially the case 

 in whooping-cough. Every serum agglutinated every strain which 

 was cultivated from a whooping-cough patient, but the culture from 

 the corresponding patient was always agglutinated to a greater ex- 

 tent than cultures from other patients. With a strain of Pfeif- 

 fer's bacillus from other sources the sera of all whooping-cough 

 patients gave a negative result. With serum of rabbits inoculated 

 with Pfeiffer's bacillus no difference could be demonstrated between 

 Pfeiffer's bacilli from pneumonia, tuberculosis, influenza, conjunctivi- 

 tis or whooping-cough. 



Odaira prepared rabbit serum against Pfeiffer's bacillus, Bac. 

 haemoglobinophilus canis, „Cohen's bacillus", and Bordet's bacillus 

 and found by agglutination and complement fixation that the two 

 first were practically the same, and the others different both from these 

 and mutually among themselves. Only one or two strains Of each 

 kind of bacterium were used. Cohen's serum reactions with me- 

 ningeal strains and other races of Pfeiffer's bacillus have already 

 been mentioned. The investigations of Olmstead & Povitzky 

 and others also showed that various strains of Pfeiffer's bacillus were 

 different, but a clear perception of the facts was not obtained 

 until the more extensive investigations during the pandemic were 

 undertaken. 



The serological reactions during the pandemic were carried 

 out with two objects in view: (1) to search for specific anti- 



