94 STUDY AND IDENTIFICATION OF BACTERIA 



organism is very slight so that. almost immediate transference, of 

 material is necessary. Flies are an important factor in Egypt. 

 The period of incubation is short, twelve to thirty-six hours. The 

 best medium is a mixture of glycerine agar and hydrocele or ascites 

 fluid. At first we rarely obtain pure cultures. The colonies are 

 dewdrop-like and first show themselves in about thirty-six hours in 

 incubator cultures. 



FIG. 29. The Koch- Weeks Bacillus. (Hansell and Sweet.) 



Diplobacillus of Morax. This organism causes mild blepharo-con- 

 junctivitis chiefly at the internal angle of the eye. They are about i or 

 2/J. long and tend to occur in pairs or short chains. Some claim that 

 they are Gram positive. 



Culturally the formation of little pits of liquefaction in Loffler's serum within 

 twenty-four hours which later become confluent may be regarded as fairly character- 

 istic. They do not grow on nutrient agar. 



After two or three days on blood-serum rather marked involution 

 forms occur. While usually causing a more or less chronic conjuncti- 

 vitis they may at times produce a keratitis. 



Bacillus of Chancroid (Ducrey, 1889). These are short cocco- 

 bacilli, occurring chiefly in chains. They show bipolar staining. They 

 grow best in a mixture of blood and bouillon. 



Bacillus of Bordet-Gengou. This bacillus was reported as the cause 

 of whooping-cough by Bordet and Gengou in 1906. (Czaplewski and 

 Reyher had previously reported oval bipolar staining organisms, as the 

 cause of pertussis, and other authors influenza-like organisms.) 



