THE BELL ANIMALCULE 19 



Under Structure insert : — 



1'. The stalk.— What is its shape? Structure? With 

 what parts of the body is it connected? Ex- 

 amine the axis of the stalk. Of what is it com- 

 posed? Look for striations in its substance. 

 Is the axis attached to the cuticle of the stalk? 

 If so, in what manner ? Compare the diame- 

 ter of the stalk with its length. How much 

 longer is the stalk when expanded than when 

 contracted ? Does the stalk correspond to any 

 part of Paramecium ? 



2'. The peristome or the rim of the body. — What 

 is its position? Shape? How is it formed? 

 Is it complete ? 



3'. The disk (lying within the peristome). — Posi- 

 tion ? Shape ? Structure ? 



7. The myopliaii layer or striated base of the 

 body. — Is it formed of cuticle, ectosarc, or en- 

 dosarc? Are the striations constant? Does 

 this correspond to any part of Paramecium ? 



T. The vestibvile or entrance to the gullet. — Posi- 

 tion ? How formed ? Has the slipper animal 

 any part corresponding to this ? 

 Make a drawing showing all of the parts visible when 

 the animal is expanded ; another showing all that can 

 be seen when the animal is contracted. 



Under Movements insert : — 



1. Of what use is the stalk ? Study the manner in 

 which the stalk contracts. What part of the 

 stalk causes the contraction? How do you 

 tell? What changes take place in the body 

 during contraction ? Note the rapidity of the 

 movements. How does the animal assume the 



