THE LIVING WORLD 



215 



AN INFUSORIAN (Vorticella) GREATLY MAGNIFIED. 



One individual has its stem contracted, while that of the other is 

 stretched out. 



y Contractile fibre in the stalk 



not contracted. 

 Cilia. 



Upper surface or disc. 

 Fibre in a contracted state. 



C.I 



d 



a 



nc Nucleus. 



p One end of the region surround- 

 ing the month. 



rf Space surrounding a particle of 

 food. 



re Contractile vesicle or space. 



vs Vestibule or chamber extend- 

 ing inwards from the mouth. 

 (After Howes. 



