778 



STARCHES OF MUSACE.E. 



Differentiation of Certain Starches of the Genus Musa. Continued. 



Histological Characteristics. Continued. 

 Lamellw General Characteristics and Number. 

 M. cavendishii {stalk): Distinct, fine rings or segments 

 of rings, tend to be wavy and irregular. 35 to 45 

 on the fairly large grains. 

 M. cavendishii {green fruit): Same as in the foregoing, 

 but more distinct. 30 to 45 on the larger grains. 

 M. sapientum: The same as in M. cavendishii (stalk), 



but more distinct. 48 to 70. 

 M. ensete: The same as in M. cavendishii (stalk). 48 

 to 54. 



Size. 



M. cavendishii {stalk): From 8 to 80m, commonly 40m. 

 M. cavendishii {green fruit): From 8 to 70m, commonly 35m- 

 M. sapientum: From 9 to 70m, commonly 46m. 

 M. ensete: From 10 to 44m, commonly 26m. 



PoLARiscopic Properties. 



Figure. 

 M. cavendishii {stalk): Usually very eccentric, distinct, 



not clear-cut, usually irregular. 

 M. cavendishii {green fruit): Same as the foregoing. 

 M. sapientum: Same as in M. cavendishii (stalk). 

 M. ensete: Same as in M. cavendishii (stalk). 



Degree of Polarization. 

 M. cavendishii {stalk): Low. 

 M . cavendishii {green fruit): Low, but distinctly higher 



than in M. cavendishii (stalk). 

 M. sapientum: Fair, higher than in M. cavendishii. 

 M. ensete: Fair, liigher than in M. cavendishii. 



Polarization with Selenite Quadrants and Colors. 



M. cavendishii {.'^talk): Quadrants not well defined, irreg- 

 ular in shape, and unequal in size. Colors not pure. 



M. cavendishii {green fruit): Quadrants same as in M. 

 cavendishii (stalk). Colors not pure. 



M. sapientum: Quadrants same as in M. cavendishii 

 (stalk). Colors not pure. 



M. ensete: Quadrants same as in M. cavendishii (stalk). 

 Colors not pure. 



Iodine Reactions. 

 Intensity and Colors. 

 M. cavendishii {stalk): Deep; bIue-\'iolet. 

 M. cavendishii {green fruit) : Deep, deeper than the fore- 

 going; blue- violet. 

 M. sapientum: Deep, deeper than in M. cavendishii; blue- 

 violet. 

 M. ensete: Deep, shghtly deeper than M. cavendishii 

 (stalk); blue-violet. 



Staining Reactions. 

 With Gentian Violet. 

 M. cavendishii {stalk): Fairly deep. 

 M . cavendishii {green fruit) : Fairly deep, deeper than 



the foregoing. 

 M. sapientum: Quite deep, much deeper than in M. 



cavendishii (stalk). 

 M. ensete: Fairly deep, slightly deeper than in M. 

 cavendishii (stalk). 



Staining Reactions. Continued. 

 With Safranin. 

 M. cavendishii {stalk): Fairly deep. 

 M. cavendishii {green fruit): Fairly deep, the same as the 



foregoing. 

 M. sapientum: Fairly deep, rather deeper than in M. 



cavendishii (stalk). 

 M. ensete: Deep, deeper than in M. cavendishii (stalk) 



Temperature of Gelatinization. 

 M. cavendishii {stalk): 67 to 68.5 C, mean 67.75. 

 M. cavendishii {green fruit): 66.5 to 68.5 C, mean 67.5. 

 M. sapientum: 67 to 69 C., mean 68. 

 M. emcte: 62 to 64 C, mean 63. 



Effects of Various Reagents. 



Reaction with Chloral Hydrate-Iodine. 



M. cavendishii {stalk): Begins in most in 60 seconds. 



All darkened in 13 minutes. 

 M. cavendishii {green fruit): Begins in most in 60 seconds. 



All darkened in 6 minutes. 

 M. sapientum: Begins in 60 seconds. All darkened in 



7 minutes. 

 M. ensete: Begins in most in 30 seconds. All darkened 



in 10 minutes. 



Reaction with Chromic Acid. 



M. cavendishii {stalk): Begins in 30 seconds; complete 

 in 4}^ minutes. 



M. cavendishii {green fruit): Begins in 15 seconds; com- 

 plete in 2J^ minutes. 



M. sapientum: Begins in 30 seconds; complete in 2 min- 

 utes. 



M. ensete: Begins in most at once; complete in 50 seconds. 



Reaction with Pyrogallic Acid. 



M. cavendishii (.stoU).' Begins in 30 seconds; complete 

 in 45 minutes. 



M. cavendishii {green fruit): Begins in 60 seconds; com- 

 plete in 45 minutes. 



M. sapientum: Begins in 60 seconds; complete in 45 

 seconds. 



M. ensete: Begins in all in 15 seconds; complete in all 

 in 15 minutes. 



Reaction with Ferric Chloride. 



M. cavendishii {stalk): Begins in 23^ minutes; complete 

 in 10 minutes. 



M. cavendishii {green fruit): Begins in lJ-2 minutes; 

 complete in 4 minutes. 



M. sapientum: Begins in 60 seconds; complete in 6 min- 

 utes. 



M. ensete: Begins in a few in 20 seconds; complete in 

 7 minutes. 



Reaction with Purdy's Solution. 



M. cavendishii {stalk): Begins at once; complete in 4 

 minutes. 



M. cavendishii {green fruit) : Begins in 15 seconds; com- 

 plete in 5 minutes. 



M. sapientum: Begins at once; complete in I'j minutes. 



M. ensete: Begins in many in 15 seconds; nearly complete 

 in 2H minutes, and complete in all in 8 minutes. 



NOTES ON THE STARCHES OF MUSA. 



The Musa starches differ in very minor degree in their gross histology; but in their reactions 

 not only is each species readily differentiated from the others, but also, in case of M. cavendishii, 

 the starch of the stalk from that of the green fruit. It is a curious coincidence that the starches 

 of the fruit of M. cavendishii and of the stalk of M. sapientum are in closer correspondence than 

 the two stalk starches. M. cavendishii and M. sapientum, in accord with botanical data, are in 

 closer agreement than either with M. ensete. 



