Histoplasmosis 573 



The lesions may be single, though they are commonly mul- 

 tiple, as many as twenty sometimes occurring simultaneously. 

 It is thought that recovery is followed by immunity. 



In 1885 Cunningham* described a protozoan organism 

 found in the tropical ulcer, the observation being confirmed 

 by Firth, f who called the bodies Sporozoa furunculosa. 

 Later, J. H. Wright J studied a case of tropical ulcer and found 

 bodies precisely like the Leishmania donovani. He gave it the 

 name Helcosoma tropicum. The great similarity to the other 

 organisms has led more recent writers to identify it with 

 Leishmania, but as it induces a local and not a general infec- 

 tion like kala-azar, it is now known as Leishmania furunculosa. 



The organism has not been cultivated. It can undoubtedly 

 be transmitted by inoculation from human being to human 

 being, and Jackson is authority for the statement that " the 

 Jews of Bagdad recognized that tropical ulcer is inoculable 

 and autoprotective years ago, and practiced vaccination of 

 their children upon some portion of the body covered by 

 clothing, in order that their faces and other exposed parts of 

 the body be not disfigured by the ulcers and the resultant 

 scars." 



The mode of transmission is not known, but as the lesions 

 usually occur where the body surface is uncovered, it may 

 be that flies or other insects are concerned in the transmission 

 of the parasites. 



HISTOPLASMOSIS. 

 HISTOPLASMA CAPSULATUM (DARLING). 



In 1906 Darling, || working at the Isthmus of Panama, ob- 

 served certain cases presenting pyrexia, anemia, leukopenia, 

 splenomegaly, and emaciation, and bearing a close resem- 

 blance to kala-azar. The disease was quite chronic, and it 

 terminated fatally. When examined at autopsy, these cases 

 showed necrosis with cirrhosis of the liver, splenomegaly, 

 pseudogranulomata of the lungs, small and large intestines, 



*" Scientific Memoirs by Medical Officers of the Army in India," 

 1884, i. 



t "British Med. Journal," 1891, Jan. 10, p. 60. 



t ''Jour, of Med. Research," x, 1904, 472. 



"Tropical Medicine," Phila., P. Blakiston's Son & Co., 1907, p. 

 478. 



|| "Jour. Amer. Med. Assoc.," 1906, XLVI, 1283; "Archiv. f. Int. Med." 

 1908, n, 107; "Jour. Exp. Med.," 1909, xi, 515. 



