328 MANUAL OF BACTERIOLOGY. 



APPENDIX. 

 PATHOGENIC PROTOZOA. 



PROTOZOA are unicellular animal organisms. As they are 

 studied by methods that have much in common with those 

 used for the bacteria they may be considered here briefly. 

 Protozoa are numerous in pond and ditch water, and these 

 species seem to be harmless. However, many diseases of 

 the lower animals are caused by protozoa, such as surra, 

 Texas fever, and coccidium disease of rabbits. Birds, 1 rep- 

 tiles and frogs 2 may show organisms in the blood, resem- 

 bling the parasites of malaria. Until recently it has been 

 doubtful whether any pathogenic protozoon has ever been 

 propagated in pure culture outside of the body of the host. 

 This has recently been accomplished by Novy and McXcal 

 for a parasite (Trypanosoma) from the blood of the rat 

 on rabbit-blood-agar. 



Amoeba Dysenterise (Amoeba Coli). Associated with 

 annt'bic dysentery and believed to be its causative agent is 

 the (juurba d \scntcr ice, more often named amcrba coli. 

 These organisms are found in the intestinal ulcers, the feces, 

 the secondary liver abscesses and the sputum (in the latter 

 only when an amoebic liver abscess has perforated into the 

 lung). The lesion in the colon is a severe inflammation 

 accompanied by necrosis chiefly of the submucous layer, and 

 leading to extensive ulceration. 3 According to Strong, at 

 least two distinct species of amoebae have been found in the 



1 Opie. MacCallum, Journal Experimental Medicine, Vol. III. 

 "Lnnirniann. AYu' Y< rk Medical Journal, January 7, 1899. 

 3 See Councilman and Laflcur. Johns Hopkins Hospital Reports, Vol. 

 II.; soo also Harris, American Journal Medical Sciences, Vol. 115, 1898. 



