GENUS ERANTHI8. 



865 



GENUS ERANTHIS. 



Eranthis is a genus of hardy perennials which includes only 7 or 8 species, all natives of 

 Southern Europe and Asia. The starch studied in this research was obtained from E. hyemalis 

 Salisb. {Helleborus hyemalis Linn.), a well-known cultivated plant in this country, often referred to 

 as the winter aconite. 



Qart No. 377. 



1 GV T 

 S 



PS CI PA CA 

 PCPS 



STARCH OF ERANTHIS HYEMALIS. (Plate 96, figs. 573 and 574. Chart 377.) 



Histological Characteristics. — In form the grains are simple. They do not occur in aggregates, 

 but frequently in clumps which may readily be broken up. There are no pressure facets. The 

 surface of the grains is rounded, but irregular owing to depressions and protuberances, some of the 

 latter being nipple-like. The conspicuous forms are ovoid, roimd, or nearly round, oval, ellipsoidal, 

 lenticular, pyriform, reniform, and various irregular forms. They are flattened, but one end may 

 be thicker than the other. 



The hilum is always fissured, but not always distinct. It is centric to varying degrees in the 

 elongated forms, and centric to slightly eccentric in the round or nearly round grains. The fissures 

 may be a single longitudinal line, somewhat ragged and irregular, or irregularly stellate, or less 

 commonly an irregular cross. Very rarely 2 hila can be 

 distinguished, and if present they are marked by fissures. 



The lamellce are invisible. 



The grains vary in size from 2 to 20fi. The dimen- 

 sions of the average grain are 14 by 10m. The common 

 size is 14/{. 



Polariscopic Properties. — The figure is usually dis- 

 tinct, centric, or slightly eccentric, and clear-cut. It may 

 be in the form of a cross or of a long line bisected at 

 each end. The lines are rather broad and may be bent 

 and otherwise distorted. 



The degree of polarization is high. It varies some- 

 what in different grains, but not much in different aspects 

 of the same grain. 



With selenite the quadrants are fairly well defined 

 and vary in shape and size. The colors are pure. 



Iodine Reactions. — With 0.25 per cent Lugol's solu- 

 tion the grains are colored fairly deeply a blue-violet; with 

 0.12.5 per cent solution the grains color lightly at first, 

 and then deeper. After heatmg in water until all the 

 grains are completely gelatinized, the solution is colored very faintly and the gelatinized grains 

 very deeply on the addition of iodine. After boiling for 2 minutes, the solution is colored deeply 

 and most of the grain-residues are colored lightly and some deeply. Almost all show a violet cap- 

 sule upon the addition of a slight excess of iodine. 



Staining Reactions. — With gentian violet the grains begin to color at once and after 30 minutes 

 are deeply stained. 



With safranin the grains begin to stain at once and after 30 minutes the color is fairly deep. 



Temperature Reaction. — The temperature of gelatinization is 51° to 52° C, mean 51.5°. 



Effects of Various Reagents. — With chloral hydrate-iodine the reaction begins in some grains in 

 15 seconds and is general in a minute. Most grains are darkened in 2}4 minutes and all in 5 minutes. 

 The process begins usually at the distal end, which becomes dark, followed by a darkening of the 

 other end and then of the margin on one side. These portions now swell somewhat and the process 

 moves inward over the whole grain. The line of demarcation between the swollen and the unswollen 

 parts is fairly well marked. There is not much swelling of the whole grain until the hilum is reached, at 

 which time there is sudden expansion in every direction. In some grains two ends are at first affected, 

 and the process invades the inner parts from these two points. The gelatinized grains are fairly large 

 and somewhat distorted, but retain some of the original form. They are uniformly dark. 



Curve of Reaction-Intensities of Starch of Eranthis 



hyemalis. 



