148 THE MORE CHRONIC INFECTIOUS DISEASES 



sumptive!" he would be pitied and perhaps not avoided at 

 all. Tuberculosis is vastly more easily transmitted than 

 leprosy. The inhuman treatment accorded to lepers is due 

 to this misapprehension. 



When the bacteria enter the mucous surfaces they are 

 carried by the lymph or blood to the exposed skin surfaces, 

 chiefly the face and hands. Here they settle in the subcu- 

 taneous tissues and nerves, producing a chronic inflammation 

 in which lepra cells are found. These are large round or oval 



FIG. 45. Schematic representation of section through a lepra nodule: 

 left side of picture gives appearance under low magnifying power; right 

 side, the appearance when highly magnified. In the latter the large lepra 

 cells are diagrammatically indicated. (Abbott.) 



cells, crowded with bacilli, lying irregularly throughout the 

 inflammatory tissues. Leprosy does not form definite 

 tubercles like tuberculosis, but the process is more diffuse; 

 nor does caseation occur. Giant cells are uncommon. The 

 bacilli produce these changes largely by poison in their 

 body and by mechanical irritation. There is some reason to 

 believe, by most recent researches, that a soluble or extra- 

 cellular poison is formed. The bacteria are discharged from 

 the patient by the sloughing of wounds, especially the ulcers 

 in the nose and throat. The dressings and cloths used to 



