206 



PROTOZOAN PARASITISM 



single parasites in the tissues, but was well marked 

 around collections of the organisms. The ulcera- 

 tions were undermined and often extended to the 



Fig. 33. 



Balanlidium coli within the tissues of the siibmucosa of the 

 ulcerated colon in balantidial dysentery. Photomicrograph x 475. 



muscular coat. The lymph nodes were hyperemic 

 and enlarged. No parasites were found in any tis- 

 sues outside the large intestine. 



From these and other investigators it may be de- 

 termined that Balantidiwn coli is capable of primary 



