786 



BOTANY AND PHARMACOGNOSY. 



I to 6 mm. in diameter. When rubbed between the fingers it is 

 reduced to a smooth powder, which is velvety to the touch. The 

 starch grains (Fig. 316, Z?) vary in shape from elHpsoidal to ovoid 



D 







O C^r\^ 





.y.\^^ 



< - 







Qd 



<Q . G^ U 



^ 







o 











Fig. 316. A, potato starch grains showing the excentral and circular point of origin 

 of growth, and lamellce; B, maranta starch grains showing fissured point of origin of growth, 

 and distinct lamellrc; C, wheat starch grains sliowing indistinct point of origin of growth, 

 and lamella:: D. corn starch grains, which are more or less polygonal in outline and have a 

 3- to 5-angled point of origin of growth. 



or oblong, and from to to 65 /t in diameter. The lamellse are 

 mostly indistinct and there is usually a transverse or crescent- 

 shaped cleft at the middle or near the broad end of the grain. 



