49 Whooping-Cough 



in the beginning of the disease. Later they become few and 

 may disappear, though the symptoms of the disease persist. 

 Cultivation. The cultures were secured upon a special 

 medium made as follows: 



I. 



l}**. Pour off the fluid. 



II. Potato extract (made as above) . . 50 c.c. ] Boil, dissolve, filter, 



0.6 per cent, aqueous NaCl 150 c.c. > and tube; 2 to 3 



Agar-agar 5 gm. J c.c. to a tube. 



III. To each tube add an equal volume of defibrinated rabbits' (or, 

 better, human) blood before cooling to the point of coagulation. Permit 

 the tubes to solidify in the oblique position. 



At first the growth is scant, but upon transplantation 

 grows better and better, until finally it may be made to 

 grow upon other media, such as blood-agar, ascitic agar, or 

 broth to which blood or ascitic fluid has been added. The 

 organism is a strict aerobe. It grows best at 37 C., but also 

 grows at temperatures as low as 5 to 10 C. On appropriate 

 culture-media Wollstein found it might remain alive for two 

 months. 



Metabolic Products. An endotoxin was found by Bordet 

 and Gengou, the method of preparing which was improved 

 by Besredka* as follows: The growth upon agar-agar is 

 removed with a small quantity of salt solution, dried in 

 vacuo, and ground in a mortar with a small measured 

 quantity of salt. Enough distilled water is then added to 

 make a 0.75 per cent, solution, after which the mixture is 

 centrifugalized and decanted. Of this preparation i to 2 

 c.c. usually killed a rabbit about twenty-four hours after 

 intravenous injection. Subcutaneous injection caused a 

 necrosis without suppuration and without constitutional 

 symptoms. Small quantities of the toxin placed in the 

 rabbit's eye caused local necrosis, with little inflammatory 

 reaction. The introduction of dead or living cultures into 

 the peritoneal cavity of guinea-pigs caused death with great 

 effusion and hemorrhage in the peritoneal tissues. 



Pathogenesis. Inoculation of monkeys with cultures of 

 the bacillus failed to produce the disease. Klimenko,t 

 however, succeeded in infecting monkeys and pups by intra- 

 tracheal introduction of pure cultures. After a period of 



* Bordet, "Bull, de la Soc. Roy. de Bruxelles," 1907. 

 t "Centralbl. f. Bakt.," etc. (Orig.), XLVIII. 64. 



