42 STARCH-GRAINS 



the Pea or Bean, lies in the centre (centric type, Fig. 20, / and 

 g), and the layers are arranged symmetrically around it. The 

 dry grains of Pea, Bean, etc., exhibit a number of radiating 



FIG. 20. Starch-grains, a-c, stages in the development of grains within 

 the chloroplasts of Pellionia ; chloroplasts shown black, ch., chloroplasts ; 

 s, starch-grains ; d and e, Potato starch ; / and g, Pea starch ; 

 h, compound starch-grain of Rice. 



cracks, which appear as dark irregular lines (Fig. 20, g) ; these 

 seem to be due to the drying up of some of the imbibed water 

 which permeates the substance of all starch-grains. 



