10 HANDBOOK OF INVERTEBRATE ZOOLOGY. 



obstruction and accumulates at the posterior end of the 

 body while the ectosarc still follows the outline of the 

 cuticle. After part of the body has been pushed past 

 the obstruction, the endosarc, with the particles which it 

 contains, flows rapidly through the narrow part into the 

 enlargement beyond. 



VI. Watch one of the larger particles in the endosarc 

 for some time, and notice that it has a motion which is 

 independent of the changes in the shape of the body. It 

 will be found by very careful examination that the endo- 

 sarc, with all its contained particles, is slowly circulating 

 around the body, up one side, and down the other, as 

 shown by the arrows in the figure. 



VII. The digestive organs. These can be most satis- 

 factorily studied after the animal has been fed with some 

 colored substance, such as powdered carmine or indigo. 

 Place a drop of water, with paramu-cia. upon a slide, and 

 mix with the water a little finely-powdered indigo ; cover 

 the specimen gently with a cover-glass, and examine with 

 a magnifying power of about two hundred diameters, 

 noticing : 



a. The currents which are caused by the small locomo- 

 tive cilia. 



b. The peristome or 8-shaped line of large cilia at the 

 anterior end of the body, by the action of which the car- 

 mine is swept into, 



c. The vestibule, a widely-open, funnel-shaped chamber 

 (Fig. 2, d) lined with cilia, and situated in the posterior 

 bend of the 8. 



d. The oesophagus, a ciliated tube which runs down- 

 wards and backwards (Fig. 2, e) into the .substance of the 

 endosarc. In this tube the particles of indigo are grad- 

 ually rolled into a pellet, and from time to time these pel- 



