BORDET-GENGOU BACILLUS 545 



strictly aerobic and in fluid cultures is best grown in wide flasks with 

 shallow layers of the medium. 



The Bordet-Gengou bacillus grows moderately at temperatures about 

 37.5° C, but does not cease to grow at temperatures as low as 5° to 10° C. 

 On blood agar and in ascitic broth it may remain alive for as long as two 

 months (Wollstein). 



Pathogenicity. — As regards the pathogenicity and etiological spe- 

 cificity of this organism for whooping-cough, no positive statement 

 can as yet be made. The fact that it has been found in many cases in 

 almost pure cultures during the early paroxysms, renders it likely that 

 the organism is the specific cause of the disease. However, in early 

 cases true influenza bacilli have been often found, and these latter seem 

 to remain in the sputum of such patients for a longer period and in 

 larger numbers than the bacillus of Bordet-and Gengou. Endotoxins 

 have been obtained from the cultures of the bacilli by Bordet and Gengou 

 by the method of Besredka.^ The growth from slant cultures is washed 

 up in a httle salt solution, dried in vacuo, and ground in a mortar with 

 a small, measured quantity of salt. Finally, enough distilled water is 

 added to bring the salt into a solution of 0.75 per cent and the mixture 

 is centrifugalized and decanted. One to two c.c. of such an extract will 

 usually kill a rabbit within twenty-four hours after intravenous inocula- 

 tion. Subcutaneous inoculation produces non-suppuratihg necrosis and 

 ulceration without marked constitutional symptoms. 



Inoculation of monkeys with the bacilli themselves by the respira- 

 tory path has failed to produce the disease. 



Speciflc agglutinins may be obtained in immunized animals which 

 prove absolutely the distinctness of this organism from Bacillus in- 

 fluenzae.^ In the serum of afflicted children the agglutination is too 

 irregular to be of value. 



Specific complement fixation with the serum of patients is reported 

 by Bordet and Gengou, but failed in the hands of Wollstein. 



MORAX-AXENFELD BACILLUS 



In 1896 Morax^ described a diplo-bacillus, which he associated 

 etiologically with a type of chronic conjunctivitis to which he appUed 

 the name " conjondivite subaigue." Soon after this, a similar micro- 

 organism was found in cases corresponding to those of Morax by Axen- 



' Bordet, Bull, de la Soc. Roy. de Brux., 1907. 

 ' Wollstein, loc. cit. ^ Morax, Ann. de I'inst. Pasteur, 1896. 



