668 



STARCHES OF AMARTLLIDACE^. 



Differentiation of Certain Starches of the Genus Galanthus. 



EElBTOLOGICAIi Chakactebistics. 

 Conxpicwma Forms. 



O. imcdia: Usually siinple, occasional compounds and 

 aggregates, some poorly defined pressure facets, 

 surface sometimes irregular owing to unequal 

 development. Spherical, ovoid, ellipsoidal, trian- 

 gular, lenticular, quadrangular. 



Q. dtoetii: Essentially the same as in (?. nwalis. 



Hilum — Form, Number, and Position. 



O. nivalis: Form distinct, usually single, small, round, 

 nxdy elongated, may be double. Usually fissured, 

 fissures usually neither deep nor very wide, single 

 or 2 or more. Position eccentric 0.20 to 0.40 of 

 longitudinal axis. 



O. dweaii: Form essentially the same as in <?. riivalis; 

 fissuration more marked. Position eccentric 0.33 

 to 0.40 of longitudinal axis. 



LamdUB — General Charaderistics and Number. 



G. nivalis: Very distinct, rather fine, continuous, may be 

 irregular. 20 to 26 on larger grains. 



G. dwesii: Fairly distinct, fine, continuous, may be irregu- 

 lar. 18 to 20 on larger grains. 



G. nivalis. 

 0. dwesii 



Size. 

 From 7 to 46/i. commonly Mn. 



From 12 to 44/i, commonly 28^. 



POLARISCOPIC PKOPEBTIES. 



Figure. 



0. nivalis: Eccentric, distinct, fairly clear-cut, lines broad, 

 may be slightly bent and otherwise distorted, fairly 

 regular. 



G. dwesii: The same as in G. nivalis, except lines broader 

 and dark areas more pronounced. 



Degree of Polarization. 



G. nivalis: Fairly high. 



G. dwesii: Fairly high, same as in G. nivalis, but dark 

 areas more pronounced. 



Polarization with Selenite — Quadrants and Colors. 



G. nivalis: Quadrants fairly well defined, fairly regular 

 in form, imequal in size. Colors fairly pure. 



0. dwesii: Quadrants the same as in G. nivalis. Colors 

 fMrly pure. 



lODiNi: Rbactions. 

 Intensity and Colors. 



G. nivalis: Deep; blue-violet. 



G. dwesii: Deep; slightly deeper than in G. nivalis; blue- 

 violet. 



Staining Reactions. 

 With Gentian Violet. 



G. nivalis: Fairly deep to deep. 



G. elwesii: Fairly deep to deep, the same as in G. nivalis. 



With Safranin. 



G. nivalis: Fairly deep to deep. 



G. elwesii: Fairly deep to deep, slightly deeper than in 

 G. nivalis. 



Temperature of Gelatinization. 



G. nivalis: 66 to 67° C, mean 66.5°. 

 G. elwesii: 69 to 71° C, mean 70°. 



Effects op Various Reaoentb. 

 Reaction with Chloral Hydrate-Iodine. 



G. nivalis: Begins immediately; complete in practically 



all in 15 minutes. 

 G. elwesii: Begins immediately; complete in practically 



all in 30 minutes. 



Reaction with Chromic Acid. 



G. nivalis: Beginsinallin20seconds; complete in 2 minutes. 

 G. dwesii: Beginsinallin20seconds; complete in 6 minutes. 



Reaction with PyrogaUic Add. 



G. nivalis: Begins in 2 minutes; complete in 45 minutes. 

 G. elwesii: Begins in 3 J^ minutes; complete in two-thirds 

 and partial in one-third in 45 minutes. 



Readion with Ferric Chloride. 



G. nivalis: Begins in some in 2 minutes; complete in 60 



minutes. 

 G. elwesii: Begins in some in IJ^ minutes; complete in 



80 minutes. 



Reaction with Purdy's Solviion. 

 G. nivalis: Begins in some in 30 seconds; complete in 



three-fourths in 1 hour. 

 G. elwesii: Begins in some in 30 seconds; complete in 



three-fourths in 1}^ hours. 



NOTES ON THE STARCHES OF GALANTHUS. 



The grains of G. nivalis are less deeply fissured, somewhat larger, and the lamellse more distinct 

 than in those of G. elwesii, otherwise the starches are essentially the same in their gross histological 

 characters. In their reactions they are close, but differ sufficiently to make possible the differentia- 

 tion of one from the other. The most noticeable differences are noted in the temperature of 

 gelatinization (difference 3.5°), and in the chemical reactions. They are essentially the same in the 

 degree of polarization and in the reaction with gentian violet, but G. nivalis has the less reaction 

 with iodine and safranin, and the higher sensitivity in relation to all of the chemical reagents. 



GENUS ALSTRCEMERIA. 



This genus of tuberous-rooted plants is composed of natives of South America, some of which 

 have a special commercial importance because of their tubers yielding the Talcahuano arrowroot 

 (see Maranta). Starches from three sources were studied: A. ligtu Linn., a native of Chile; A. bras- 

 iliensis Spreng., a native of Brazil; A. aurantiaca (aurea) Don., a native of Chile. The first prepa- 

 ration was obtained from the Materia Medica Museum of the University of Pennsylvania, in which 

 it was deposited about 50 years ago, at which time the specimen was received by Dr. Carson, then 

 professor of materia medica and therapeutics, and recorded as being derived from A. ligtu. 



