A TYPICAL ORGANELLE — SHAFT 



15 



a. 



c. 



Fig. 4. Diagrams showing the structure of a cilium. a, 

 Structures seen in a longitudinal section, b, Transverse section 

 of the ciliary shaft with the typical arrangement of internal 

 fibrils, c, The arrangement of fibril triplets in the basal body, 

 showing the position of the third subfibril C, and the twist of 

 the peripheral triplets. Compare with Plates I to IV. 



