470 



STARCHES OF AROIDE^. 



Differentiation of Certain Starches of the Pith of the Genus Dieffenbachia. Continued. 



Effects of Various Reagents. Continued. 

 Reaclion with Pyrogallic Acid. 



D. seguine var. nohilis: Begins in 30 seconds; complete 

 in 5 minutes. 



D. seguine var. maeulala: Begins in IJ^^ minutes; com- 

 plete in 7 minutes. 



D. seguine var. irrorata: Begins in 1 minute; complete 

 in 8 minutes. 



D. illustris: Begins in IJ^ minutes; complete in 10 min- 

 utes. 



Reaclion icith Ferric Chloride. 



D. seguine var. nohilis: Begins in 2 minutes; complete in 

 all in 20 minutes. 



D. seguine var. maeulala: Begins in 2 to 5 minutes; com- 

 plete in 2.5 minutes. 



D. seguine var. irrorata: Begins in 2 minutes; complete 

 in 15 minutes. 



Effects of Various Reagents. Continued. 



Reaction with Ferric Chloride. Continued. 



D. illustris: Begins in 2 minutes; complete in 30 minutes. 



Reaclion with Purdy's Solution. 



D. seguine var. nohilis: Begins in a minute; in 45 minutes 



all the grains are partially but none completely 



gelatinized; practically no further reaction in an 



hour. 

 D. seguine var. maeulala: Begins in some in 2 minutes. 



In 1 J 2 hours about half of the grains are partially 



gelatinized. 

 D. seguine var. irrorata: Begins in one-third in 2J-2 



minutes. In 13^2 hours all are partially gelatinous. 

 D. illustrU: Begins in 2 minutes. In 1 3-i hours not more 



than about one-fourth of the grains show any 



signs of gelatinization. 



Differentiation of Certain Starches of the Corte.v of the Genus Dieffenbachia. 



D. 



D. 



D. 



D. 



Histological Characteristics. 

 Conspicuous Forms. 



seguine var. nohilis: Essentially the same as in pith 

 starch, excepting that the grains are almost 

 wholly of the cylindrical and elliptical types. 

 Secondary lamella; rare. 



seguine var. miwulata: Essentially the same as in 

 pith starch, except a marked tendency to the 

 elliptical form, and to less of the peculiar odd 

 shapes due to secondary lamellse. 



seguine var. irrorata: Essentially the same as in pith 

 starch, but with marked tendency to the elliptical 

 form and to a lessening in the number of freakish 

 forms due to secondary lamelUc. 



illustris: Essentially the same as pith starch, but 

 the grains are narrower, with much greater tend- 

 ency to hook forms. 



Ililuni Form, Number, and Position. 

 D. seguine var. nohilis: Form the same as in the pith, 



but not fissured. Position more eccentric than 



in pith starch. 

 D. seguine var. nmculata: Form same as in the iiith. 



Position eccentric, about the same as in pith starch. 

 D. seguine var. irrorata: Form same as in the jiith. 



Position eccentric, about the same as in pith starch. 

 D. illuslri-^: Form fairly distinct, small, round, not fis.sured. 



Position eccentric, about the same as in pith starch. 



Lamellm General Characteristics and Numhcr. 



D. seguine var. 7iohilis: Same as in the pith, but finer. 

 Number about the same as in pith starch. 



D. seguine var. maeulala: The same as in the pith. Num- 

 ber not so many, as a rule, as in pith starch. 



D. seguhie var. irrorata: Form same .as in the pith. Num- 

 ber about the same as in pith starch. 



D. illustris: Form about the same as in pith starch, but 

 somewhat less distinct. Number about the same 

 as in pith starch. 



Size. 



D. seguine var. nohilis: From 4 to 49m, commonly 24^. 



D. seguine var. mnculata: From 7 to 52m, commonly 27m. 



T). seguine var. irrorata: From 4 to 47m, commonly 27m. 



D. illustris: From 5 to 50m, commonly 25m. 



PoLARiscopic Properties. 

 Figtire. 

 D. seguine var. nohilis: The same as in pith starch, but 



more eccentric. 

 D. seguine var. macidata: The same as in pith starch. 

 D. seguine var. irrorata: The same as in pith starch. 

 D. illustris: The same as in pith starch. 



PoLARiscopic Properties. Continued. 



Degree of Polarization. 



D. seguine var. nohilis: Fair, lower than in pith starch. 

 D. seguine var. maeulala: High, lower than in pith starch. 

 D. seguine var. irrorata: Fair, distinctly lower than in 



pith starch. 

 D. illustris: Fairly high, not so high as in pith starch. 



Polarization with Selenite Quadrants and Colors. 



D. seguine var. nohilis: Quadrants same as in pith starch. 



Colors with lower purity than in pith starch. 

 D. seguine var. maeulala: Quadrants same as in pith 



starch. Colors same as in pith starch. 

 D. seguine var. irrorata: Quadrants same as in pith starch. 



Colors same as in pith starch. 

 D. illustris: Quadrants same as in pith starch. Colors 



with lower purity than in pith starch. 



Iodine Reactions. 

 Intensity and Color. 



D. seguine var. tiohilis: Deep, the same as in pith starch; 

 blue-violet. 



D. seguine var. maeulala: Deep, the .same as in pith starch; 

 blue- violet. 



D. seguine var. irrorata: Deep, deeper than in pith starch; 

 blue- violet. 



D. illustris: Deep, not so deep as in pith starch; blue- 

 violet. 



Staining Reactions. 



With Gentian Violet. 



D. seguine var. iiobilis: Deep, lighter than in pith starch. 

 D. seguine var. maeulala: Deep, same as in pith starch. 

 D. seguine var. irrorata: Deep, same as in pith starch. 

 D. illustris: Deep, lighter than in pith starch. 



With Safraniri. 



D. seguine var. nohilis: Fairly deep, not so deep as in 



pith starch. 

 D. seguine var. macidata: Fairly deep, not so deep as in 



pith starch. 

 D. seguine var. irrorata: Fairly deep, not so deep as in 



pith starch. 

 D. illustris: Fairly deep, not so deep as in pith starch. 



Temperature of Gelatinization. 



D. seguine var. nohilis: 6S.5 to 70.5 C, mean 69. 

 D. seguine var. maeulala: 70 to 71.2 C, mean 70.6. 

 D. seguine var. irrorata: 68 to 69.5 C, mean 68.75. 

 D. illustris: 69 to 71 C, mean 70. 



