(J20 INFECTION AND IMMUNITY. 



numbers in the testicles. Hansen states, however, 

 that he has never found them in the female gen- 

 erative organs. 

 Location The presence of large masses of bacilli in leprous 



of Bacilli. ,. , . . ,. m 



tissues is a characteristic of the disease. To a large 

 extent they are intracellular and they are often 

 grouped in such a way as to resemble bundles of 

 cigars. Hansen believes that the bacillus is essen- 

 tially an intracellular parasite, and that it becomes 

 extracellular only as a result of degeneration and 

 disintegration of infected cells. Unna, on the 

 other hand, considers their location in lymph 

 spaces as most characteristic. They appear to be 

 carried to distant parts through the lymphatics. 

 Certain large vacuolated cells, the lepra cells of 

 Virchow, the globi of Hansen, which are filled to 

 bursting with the leprosy bacilli, are characteristic 

 of the disease. Unna and others consider these 

 bodies as zooglear masses rather than as intracel- 

 lular accumulations, and Kanthack interprets them 

 as bacillary thrombi in the lymphatic vessels. The 

 nodules, or lepromas, consist of granulation tissue, 

 containing many round and epithelioid cells, lepra 

 cells and occasional multinuclear giant cells. In 

 cutaneous macules columns of round cells surround 

 the blood vessels, there is some proliferation of 

 epithelioid cells, but relatively few bacilli. The 

 bacilli are most numerous in the nodular lesions. 

 They are found in the Glissonian tissue of the liver, 

 in the pulp and follicles of the spleen, in the glom- 

 eruli and interstitial tissue of the kidneys when 

 these organs are involved, in the nerves in both 

 the nodular and maculoanesthetic forms of the 

 disease, and in the vascular endothelium. They 

 have been demonstrated often in the ganglionic 



