ROOT STRUCTURES 



65 



Fig. 15. Diagram of the root structures of adoral mem- 

 branelles of Stentor. The root fibrils (r), which are attached 

 to the kinetosomes {k) of component cilia of the membranelle, 

 are cross-linked in hexagonal array (inset); as they run deeper 

 into the cytoplasm, the root fibrils are formed into bundles {rbf) 

 which link with the bundles from other membranelles to form 

 the basal fibre {bf) (from Randall and Jackson, 1958). 



