Balantidium Diarrhea 705 



first observed by Malmsten* in 1857 in the intestines of a 

 man who had suffered from cholera two years before and had 

 ever since suffered from diarrhea. Upon investigation an 

 ulceration was found in the rectum just above the internal 

 sphincter. In the bloody pus from this ulcer numerous 

 balantidia were seen swimming about. Although the ulcer 

 healed, the diarrhea did not cease. Since this original ob- 

 servation and up to 1908 Braunf had been able to collect 

 142 cases of human infection. In all of these cases the pres- 

 ence of the balantidium was accompanied by obstinate diar- 

 rhea with bloody discharges (dysentery) in some, and many 

 of the cases ended in death. 



Morphology. The Balantidium coli is an infusorian 

 micro-organism of ovoid or ellipsoidal form, measuring from 

 30 to 200 fi in length and from 20 to 70 [i in breadth. The 

 body is surrounded by a distinct ectosarc completely covered 

 by short fine cilia. The anterior end, which is usually a little 

 sharper than the posterior, presents a deep indentation, the 

 peristome, which continues, in an infundibuliform manner, 

 deeply into the endosarc. The peristome is surrounded by a 

 circle of longer cilia adoral cilia than those elsewhere 

 upon the body. At the opposite pole there is a small open- 

 ing in the ectosarc, the anus. The mouth is the simple ter- 

 mination of the infundibuliform extension of the peristome 

 and opens directly into the endosarc, so that the small bodies 

 upon which the organism feeds, and which are continually 

 being caught in the vortex caused by the rapidly vibrating 

 adoral cilia are driven down the short tubulature directly 

 into the endosarc. 



The endosarc is granular and contains fat and mucin 

 granules, starch grains, bacteria, and occasionally red and 

 white blood-corpuscles. 



There are usually two contractile vacuoles, sometimes more, 

 and as the quiet organism is watched these large clear spaces 

 can be seen alternately to contract and expand. 



There are two nuclei. The larger, or macronucleus, is bean- 

 shaped, kidney-shaped, or, more rarely, oval. The smaller, 

 the micronucleus, is spherical. There is no digestive tube; 

 the nutritious particles are directly in the endosarc, in which 

 they are digested, any residuum being extruded from the 

 anus. 



! "Archiv. f. pathologische Anatomic," etc., xn, 1857, p. 302. 

 t "Tierische Parasiten des Menschen," Wiirzburg, 1908. 

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