BACILLUS DIPHTHERIA 519 



present, infection with this bacillus should always be suspected. The 

 consequent disease depends, in part, upon the mechanical disturbance 

 caused by these false membranes and, in part, upon the systemic poi- 

 soning with the toxin which the bacilli produce. Although the diph- 

 theria bacillus has been found after death in the spleen and liver, we 

 have no data which would justify the assumption that a true diph- 

 theria-septicemia may occur during life. It is probable that in those 

 cases which Baginsky l has called the septicemic form of diphtheria, 

 Bacillus diphtherise has merely opened a path by which accompanying 

 streptococci have gained access to the lymphatics and the blood stream. 

 The most frequent sites of diphtheritic inflammation are the mucous 

 membranes of the throat, larynx, and nose. They have also been 

 found in the ear, upon the mucous membrane of the stomach and the 

 vulva, and upon the conjunctiva and the skin. According to Loeffler, 

 Strelitz, 2 and others, the bacillus may, by extension from the larynx, give 

 rise to a true diphtheritic broncho-pneumonia. 



For most of the usual laboratory animals the diphtheria bacillus is 

 very pathogenic. Dogs, cats, fowl, rabbits, and guinea-pigs are suscep- 

 tible. Rats and mice are resistant to all but extremely large doses. 

 False membranes, analogous in every way to those found in human 

 beings, have been produced in many animals of susceptible species, but 

 only after inoculation with the bacillus had been preceded by mechanical 

 injury of the mucosa. The lesions produced in animals by subcutaneous 

 inoculation present many characteristic features which facilitate the 

 bacteriological recognition of the diphtheria bacillus. Small quantities 

 (0.5 to 1 c.c.) of a virulent broth culture, given subcutaneously to a 

 guinea-pig, may produce the gravest symptoms and within six to eight 

 hours the animal may show signs of great discomfort. Death occurs 

 u .inlly within thirty-six to seventy-two hours. Upon autopsy the point 

 of inoculation is soggy with serosanguineous exudate; neighboring 

 lymph-nodes are edematous. Lungs, liver, spleen, and kidneys are 

 congested. There may be pleuritic and peritoneal exudates. Charac- 

 teristic, and almost pathognomonic, is a severe congestion of both 

 suprarenal bodies. The gastric ulcerations recently described by Rose- 

 nau and Anderson 3 may occur, but are by no means regularly found 

 (two out of fifty in our series 4 ). 



1 Baginsky, "Lehrbuch d. Kinderkrankheiten." 



2 Strelitz, Arch. f. Kinderheilk., 1891: 



3 Rosenau and Anderson, Jour. Inf. Dis., iv, 1907. 



4 Zinsser, Journ. Med. Res., xvii, 1907. 



