20 THE MOLECULAR ARCHITECTURE OF PLANT CELL WALLS 



largely the properties of a single cell. This, together with other simpli- 

 fications inherent in fibre structure, which will appear later, enables the 

 fundamental structural features of the material constituting the walls of 

 plant cells to be determined with some certainty. Investigation of struc- 

 ture in other cell types and in more complicated tissues then resolves 

 itself into the application of the knowledge thus obtained to the more 

 complex forms. Even with the fibres, however, there is the complexity 

 that the cells are not strictly the continuous hollow cylinders into which 

 physicists, for the best of reasons, prefer to sublimate their ideas. The 

 long, tapering ends scattered up and down any naturally occurring 

 bundle of fibres introduce some degree of uncertainty into the orienta- 

 tion of the constituent cell walls. As far as the investigation of the 

 fundamental features associated with the crystallinity of the walls is 

 concerned, this does not have any important effect; but it cannot be 

 ignored when attempting completely to delineate the properties of any 

 single cell from the properties of a bundle. 



