OBSERVATIONS ON A FLAGELLATE OP CERCOMONAS. 245 



For fixing the flagellates the most useful fixative has been 

 Schaudinn's mixture of two thirds saturated aqueous solution 

 of sublimate and oue tiiird alcohol, slightly acidified with 

 acetic acid. This has been used in the manner just described 

 by Schaudinn or in a slightly modified form. The films are 

 best stained with iron-hsetnatoxylin. 



DBSCRIPTfON OF THE LiVING FlAGELLATES. 



When examined in a drop of liquid medium on a slide the 

 Text-fiffs. 1-8. — Drawin2;s from life. 



Text-fi«, 1. 



Text-fig. 2. 



Aniceboid form in early division 

 stage. 



Amojboid form. 



flagellates appear as pear-shaped organisms, with a long 

 flagellum, about twice the length of the body, arising from 

 the blunt end. The posterior end of the body is, as a rule, 

 drawn out to a tine and tapering point. By the constant 

 lashing of this long anterior flagellum the* animal is drawn 

 along. Sometimes the flagellum is, as it were, hooked around 

 some distant object, and by its flexion pulls the body towards 

 this point. The posterior end of the body, which, as stated 

 above, is also a flagellum, moves much less vigorously than the 

 anterior. Its movements may be quite passive, being only 

 the accidental changes in position produced by the changes 



