422 HEMOGLOBINOPHILIC BACILLI 



into rabbits frequently kill them within twenty-four to forty-eight 

 hours. Subcutaneous injections of autolysates may cause local 

 necrosis, but generalized symptoms fail to appear. Similar results 

 have been obtained with endotoxin obtained by grinding the bacilli 

 to an impalpable powder and injecting a saline suspension of it. 1 



Pathogenesis. Animal. Klimenko 2 and Franker 3 produced a catarrh 

 of the respiratory mucosa of monkeys and young dogs by intratracheal 

 injections of B. pertussis suspended in salt solution. A febrile reac- 

 tion appeared after three to four days and several of the animals died 

 within two to three weeks. The bacilli were recovered from the 

 bronchial mucus, bronchi, and from the areas of bronchopneumonia 

 which developed in the lungs. No characteristic paroxysms were 

 induced, although Klimenko stated that sneezing and coughing were 

 noticed. Wollstein 4 has pointed out a possible source of error in the 

 dog experiments: she finds that those dogs which die after injections 

 of B. pertussis succumb to canine distemper; the lesions of the respira- 

 tory tract are readily accounted for on this basis, and the blood of 

 the animals fails to react specifically with the Bordet-Gengou bacillus. 



Human. There are no postmortem lesions characteristic of whoop- 

 ing-cough. Bronchopneumonia is the most common complication 

 seen at autopsy. Mallory and Hornor, 5 and Mallory, Hornor and 

 Henderson 6 have advanced an interesting explanation for the parox- 

 ysms of whooping-cough. They find that the ciliated epithelium of 

 the respiratory tract is denuded in places and the cilia plastered down 

 to such an extent as to interfere with the free removal of mucus by 

 the mechanical action of the bacteria. When mucus accumulates in 

 sufficient amount, it is forcibly expelled by a prolonged violent parox- 

 ysm of coughing. These experiments were made upon animals; the 

 frequent occurrence of B. bronchosepticus or a closely-related bacillus 

 in the respiratory tracts of laboratory animals, which produces similar 

 lesions to those seen in canine distemper, should be borne in mind in 

 interpreting these results. 



Immunity. Whooping-cough is more commonly a disease of chil- 

 dren, and recovery from one attack appears to confer lifelong immunity 

 as a rule. 



1 Bordet and Gengou, Centralbl. f. Bakt., Ref., 1909, xliii, 273. 



2 Centralbl. f. Bakt., Orig., 1909, xlviii, 64. 



3 Munch, med. Wchnschr., 1908, p. 1683. 



4 Loc. cit. 



6 Jour. Med. Research, 1912, xxvii, 115. 

 6 Ibid., 1913, xxvii, No. 4. 



