WALL STRUCTURE IN THICK CELL WALLS 119 



TABLE yi—contd. 



TABLE VIA 



Correspondence between direction of m.e.p. and of 



striations in elongated cells. Both directions are 



defined by the angle they make to cell length 



* Standard error. 



t The following m.e.p. s were calculated from the optical data on whole walls to 

 exclude the effects of the primary wall. The error is the sum of the experimental 

 errors, not the standard error. 



