BALANTIUIUM COLI 2OI 



also red and white blood corpuscles. There are usually two con- 

 tractile vacuoles, seldom more. The anus (cytopyge) opens at the 

 posterior extremity. The macronucleus is bean- or kidney-shaped, 

 rarely oval ; the micronucleus is spherical. 



Balantidiiiui coli lives in the large intestine of man, in the rectum of 

 the domestic pig, and has been found in monkeys. It propagates by 

 transverse division, but conjugation and encystment are known to 

 take place. 1 Transmission to other hosts is eft'ected by the cysts of 

 the parasite (fig. 114). 



Balantidium coli, first seen by Leeuwenhoek, was described 

 by Malmsten in 1857 in a man aged 35 years, who had two 

 years previously suffered from cholera, and since then had been 

 subject to diarrhoea. The examination showed an ulcer in the rectum 

 above the mid sphincter ani, in the sanguineous purulent secretion of 

 which numerous Balantidia were swimming about. Although the 

 nicer was made to heal, the diarrhcea did not cease and the stools 

 contained numerous Balantidia, the number of which could only be 

 decreased by extensive enemas of hydrochloric acid. 



The second case related to a woman who was suffering from 

 severe colitis, and who died ten days after admission. The mal- 

 odorous, watery evacuations contained innumerable Balantidia, in 

 addition to pus, and at the autopsy the anterior portion of the large 

 intestine was found to be infested with them. 



Subsequently this parasite has often been observed in human 

 beings, and various cases have been recorded. These occurred in 

 Russia, Scandinavia, Finland, Cochin China, Italy, Germany, Serbia, 

 Sunda Islands, Philippine Islands, China, and in other parts of Asia 

 and in America. Other cases were reported by Askanazy, Ehrnroth, 

 Klimenko, Nagel, Koslowsky, Kossler, Waljeff, Strong and Musgrave, 

 Glaessner 2 and others. Sievers found B. coli very common in Finland. 



In the majority of the cases described by Sievers from Finland, 

 and in other cases from Central Europe, the patients suffered from 

 obstinate intestinal catarrh, which did not always cease even after 

 the Balantidia had disappeared. On the other hand, Balantidia have 

 occasionally still been found to persist, though in small numbers, after 

 the catarrh has been cured. Some authors, nevertheless, do not 



1 According to Gourvitch (" Bal. coli. Darmk. d. Menschen," Rnss. Arch. f. Path., klin. 

 med. n. Bact., Petrograd, 1896), the conjugated Balantidia are supposed to fuse with each 

 other and form oval cysts two or three times the size of the free organisms, and to divide into 

 numerous globules within the cystic membrane ; the process, however, has hitherto not been 

 confirmed. The supposed Balantidium cysts appeared in two patients who were simultaneously 

 suffering from Dibothriocephahis latus, after the administration of anthelminthics. It therefore 

 seems, according to the description, that in reality these forms were actually abnormally large, 

 possibly swollen, young eggs of the tape-worm mentioned. 



2 Centralbl.f. Bakt., Orig., xlvii, p. 351. 



