OBSERVATIONS ON A FLAGELLATE OF CERCOMONAS. 249 



When seen ifc is inert and only moves in a passive manner. 

 It seems to take little share in movements ot" progression. 



On the surface of the agar medium the organism is generally 

 of the amoeboid form. 



At the edge of the hanging-drop prepai'ations or on the 

 surface of the agar it is eas}- to watch these amoeboid forms 

 ingesting- food by surrounding objects with pseudopodia. As 

 a rule the amoeboid foi-ms contain many more food-vacuoles 

 than those swimming in the deeper layers. 



Text-fig. 7. 



Less regular encysted form. 



Reproduction is by longitudinal division. There is first 

 multiplication of the flagella, whether by new fomnation oi- 

 division of those already existing has not been determined. 

 The nucleus next divides. The karyosome is divided into two 

 parts, and finally the elongated nuclear membrane becomes 

 constricted and two nnclei are formed. After a short time 

 the protoplasm becomes drawn out and finally a constriction 

 appears, which ultimately ends in complete division. The 

 process of this division is very readily watched on the cover- 



