64 MANUAL OF HUMAN PROTOZOA 



form, and measures 10-30|j long. There are two equally 

 long flagella at the narrow end, near which is located a 

 nucleus. A contractile vacuole is present near the posterior 

 end. Stained individuals show that the flagella arise from 

 points just in front of the nucleus. 



Cysts. The cyst (Fig. 14, 5) is spherical and about 7-14|j 

 in diameter. The cyst wall may show 3-8 small pores. The 

 nucleus may be faintly seen near the center. When stained, 

 the cyst wall is seen double-layered. The pores are sur- 

 rounded by slight thickenings of the wall. The majority 

 of cvsts are uninucleate. 



3, Bodo caudatus (Dujardin 1841) 



This is a small biflagellated organism which is very 

 common in stagnant water and moist soil. 



Trophozoites. Actively motile; body polymorphic, but 

 usually elongate. About 10-20m long (Fig. 14, 6, 7). Its 

 anterior end is bluntly pointed, while its posterior end is 

 attenuated. The body is somewhat compressed. There are 

 a vesicular nucleus with a large endosome near the center 

 of body, and bacteria in food vacuoles. Two flagella arise 

 in the anterior end. The anterior flagellum is short, but 

 the trailing flagellum is long. A small slit, the cytostome, 

 and a small contractile vacuole are located near the flagel- 

 lated end. When fixed and stained, the body becomes more 

 rounded. The nucleus contains a large central endosome 

 and there are seen radiating strands between the latter 

 and the membrane. The anterior flagellum is about the 

 body length, but the posterior one is about twice the body 

 length. Near the blepharoplasts there is a large rounded 

 parabasal body. 



