DIPHTHERIA. 211 



neous connective tissue. Then, in the presence of fever, 

 there develop pleuritic effusions, swelling and redness of 

 the adrenal glands, hemorrhages into the structure of the 

 lymphatic glands, and death, preceded by decline of the 

 temperature, occurs in the course of from twenty-four to 

 forty-eight hours. If the virulence of the bacillus is slight, 

 the disease is protracted : it may last three, four, or five 

 days, and even several weeks. In the less susceptible rabbit 

 the slow course is the rule. Under these circumstances 

 there occur true diphtheric palsies, at first involving the 

 posterior extremities of the animal, then the anterior, and 

 finally the muscles of the neck. Death takes place after 

 marked emaciation. At the autopsy fatty degeneration of 

 the liver and the kidneys is found, and also inflammatory 

 changes in the spinal cord and the nerves. If the virulence 

 is still further diminished, the constitutional symptoms 

 (fever) and the remote manifestations (pleuritis, palsies) are 

 less conspicuous. After recovery from the local inflamma- 

 tory process, which terminates in necrosis of the skin, the 

 animal may be restored to health. 



Physiology of the Disease in Animals. Whether 

 their virulence be great or slight, the bacilli remain at the 

 site of introduction, and, as a rule, they do not penetrate 

 more deeply into the organism. Multiplication of the 

 bacilli at the point of injection takes place only to a small 

 extent, and only at the beginning in the first six or eight 

 hours ; later, the number of bacteria rather diminishes. 

 They may, however, survive for a long time, and they have 

 been found alive after weeks among the necrotic portions 

 of skin at the point of injection. The constitutional dis- 

 ease of animals results exclusively from the poison gene- 

 rated by the bacteria : the diphtheria-toxin. The disease 

 developed in animals by diphtheria-bacilli is, thus, a purely 

 toxic one. If the poison alone, without the bacilli, is intro- 

 duced into the bodies of animals, there result the same 

 morbid manifestations, with . the exception of the false 

 membrane, and especially the palsies, just as after inocula- 

 tion with the bacilli themselves. In experimental intoxi- 

 cation of animals a bouillon-culture, several weeks old, is 

 employed for inoculation whose reaction, originally alka- 

 line, has become acid and is again rendered alkaline, and 

 which has been freed of bacteria by filtration through a 

 porcelain filter (Chamberland filter in which the fluid con- 



