Balantidium Diarrhea 707 



out by Gourvitsch,* studied by Leger and Duboscq,f and 

 further confirmed by BrumptJ. In the process of conjuga- 

 tion two individuals come together, become attached length- 

 wise, and fuse into a single large organism that forms a cyst 

 several times as large as a balantidium, and with contents no 

 longer recognizable as such. The contents of this cyst 

 eventually divide into a number of spheres, but how these 

 subsequently develop appears not to have been deter- 

 mined. 



Habitat. The balantidium is unknown except as a para- 

 site of the colon. It is very common in hogs and has been 

 found in the orang-outang, in certain lower monkeys 

 (Macacus cynomolgus), and in man. 



Cultivation. The organism quickly dies when trans- 

 planted to artificial media and has not yet been cultivated 

 artificially. 



Pathogenesis. The presence of the organisms, in whatever 

 kind of animal, gives rise to colitis, which is at first catarrhal, 

 but soon becomes more or less ulcer ative. Some doubt has 

 been expressed as to the exact role of the balantidia in 

 the causation of the inflammation, some believing them to be 

 rather accidental factors than the true etiologic excitants. 

 As the organisms descend into the ulcerated tissues and from 

 the denuded surfaces invade the lymphatics, there seems to 

 be little doubt of their pathogenic activity. 



Animal Inoculation. Experiments made by Casagrandi 

 and Barbagallo, Klimenko, || and others upon kittens and 

 pups have failed to produce the disease even when the colon 

 was already inflamed. Brumpt,** on the contrary, succeeded 

 in reproducing it in monkeys and pigs by introducing the 

 encysted organisms into the already inflamed intestine via the 

 anus. 



Lesions. In the majority of fatal cases postmortem ex- 

 amination of the colon shows it to be in a state of catarrhal 

 inflammation with numerous superficial ulcerations with con- 

 siderable surrounding infiltration of the mucosa. Twenty- 



*"Russ. Archiv. f. Path. klin. Med. u. Bact. St. Petersb.," 1896, 

 quoted by Braun. 



t "Archiv. de Zool. Exper.," 1904, n, No. 4. 

 J "Compt.-rendu de la Soc. de Biol.," July 10, 1909. 

 "Bal. coli," etc., Catania, 1896, quoted by Braun. 

 || "Beitrage zur. Path. Anat. u. allg. Path.," 1903, xxxn, 281. 

 ** "Precis de Parasitology," 1910, 152. 



