254 Drji Matter and Nitrogen in the Potato Tuber 



In each tuber the core whether longitudinal, diagonal or transverse 

 contains a distinctly smaller proportion of dry matter than the quarter 

 which is a more nearly representative sample of the whole tuber. 



transverse core 



I diagonal core 



FiR. 12. 



quarter 



Fig. 13. 



Division of the tuber into sectors as in Fig. 13 gave the following 

 results : 



Table XV. 



When one sector is taken as a sample there may be a difference from 

 the mean of nearly 2 per cent, dry matter (sector d). When radially 



