STARCH 



403 



as East Indian arrowroot ; that of Mantfiot utilissima, Pohl (N.O. 

 Euphorbiacece) , and that of Ipomoea Batatas, Choisy (N.O. Con- 

 volvulacece) , as Brazilian arrowroot; that of Canna edulis, Edwards, 



FIG. 222. Potato Starch. Magnified 300 diam. (Tschirch.) 



and other species of Canna (N.O. Scitaminece) as Queensland 

 arrowroot, &c. 



The grains of maranta starch resemble in general appearance 

 those of potato starch, but they are as a rule decidedly smaller, 



FIG. 223. Maranta Starch. Magnified 300 

 diam. (Tschirch.) 



averaging only 30//. to 45/i in length (exceptionally 65/z, to 75/x) and 

 24fjL to 30/A in breadth. They are rather irregularly ovoid in shape 

 and exhibit distinct concentric striae. The position of the hilum is 

 usually indicated by a cleft or by three or four radiating fissures, 



