214 



the whooping-cough cultures on Bordet's potato glycerine 

 blood agar after a month's keeping in the cold room. 



All the facts mentioned prove that Bordet's bacillus is 

 distinct from Pfeiffer's bacillus in a series of perfectly con- 

 stant properties and also in that the various strains of the 

 former species are more uni"orm than in the case of Pfeif- 

 fer's bacillus. 



It must also be asserted that the „cultural" characters 

 are at least as useful in the detection of the whooping-cough 

 bacillus as the serological tests. 



3. Bacillus Haemoglobinophilus Canis. 



As a further test whether the methods used in the investi- 

 gation of Pfeiffer's bacillus permit a clear distinction between 

 this group and closely allied species, I procured some strains 

 of the organisms which, according to the works of Fried- 

 rerger and Krage, occur very commonly in the widely di- 

 stributed blenorrhoea of the prepuce in dogs. 



They are described as Gram negative rods which grow on 

 blood agar in small colonies of similar appearance to those 

 of Pfeiffer's bacillus and which do not grow on ordinary or 

 ascitic agar, even after a year's cultivation on artificial media. 

 According to Friedrerger they are able, in contrast to Pfeif- 

 fer's bacillus, to grow on agar containing ferratin instead of 

 haemoglobin, and they are satisfied with a particularly small 

 concentration of haemoglobin. Krage obtained weak growth 

 in broth containing sugar, which accords well with his state- 

 ment that it turns haemoglobin broth acid. It is apparently 

 able to ferment and make use of the sugar. It is also stated 

 that the growth is not increased by other bacteria. Friedrerger 

 found that the culture decolorised haemoglobin but according 

 to Krage this was not the case. On keeping they died out 

 just as quickly as Pfeiffer's bacillus. 



Odaira compared one strain of Bacillus haemoglobinophi- 

 lus canis with two strains of Pfeiffer's bacillus and found 

 them to be serologically identical. 



Thanks to Prof. Carl Hansen's kindness I was able (5. 

 VII. 20) to undertake inoculations from the inner surface of the 



