INVESTIGATION OF STRUCTURE IN PLANT CELL WALLS 



4^ 



We therefore merely calculate the weight of these residues and divide 

 by the volume of the unit cell. Thus: 



^=(2)(324)(l-6604)/(10-3)(8-35)(7-9) sin 84°=l-59. 



The density of cellulose never in fact reaches this figure and this is 

 undoubtedly due to the presence of periodic breaks in the regularity of 

 structure as mentioned above. It should be clear that the density of 



Fig. 25. Modern conceptions of micellar structures. 



(a) The "fringed micelle" as suggested by Kratky and Frey-Wyssling. 



(b) The continuous, deformed structure proposed by Meyer (1940). (Reproduced 

 from High Polymers, Vol. IV, Natural and Synthetic High Polymers, by 

 K. H. Meyer, Interscience publishers, 1942 (29(6)), by courtesy of the author.) 

 In the particular interpretation given in (a) two molecular chains such as those 

 delineated by circles behave as a single chain traversing the whole structure 

 since the ends A, A', lie in the crystalline region (marked by dark lines). 



