740 



STARCHES OF IRIDACEiE. 



Differentiation of Certain Starches of the Genus Freesia. Continued. 



Effects of Various Reagents. Continued. 

 Reaction with Chromic Acid. 



F. refracta var. alba: Begins in a minute; complete in 

 4 minutes. 



F. refracta var. leichtlinii: Begins in IJ^ minutes; com- 

 plete in 3 minutes. 



Reaction with Pyrogallic Acid. 



F.refraetav&T.alba: Begins in some in 2 minutes; allpartial- 

 lyand one-half completely gelatinized in 30 minutes. 



F. refracta var. leichtlinii: Begins in 2 minutes; all partially 

 and one-half completely gelatinized in 20 minutes. 



Effects of Various Reagents. Continued. 



Reaction with Ferric Chloride. 



F. refracta var. alba: Begins in some in 2 minutes; com- 

 plete in 30 minutes. 



F. refracta var. leichtlinii: Begins in some in 2}^ minutes; 

 complete in 30 minutes. 



Reaction with Purdy's Solution. 



F. refracta var. alba: Begins in some in IJ^ minutes; 



complete in half in 45 minutes. 

 F. refracta var. leichtlinii: Begins in some in 2J^ minutes; 



complete in half in 30 minutes. 



NOTES ON THE STARCHES OF FREESIA. 



The two starches examined, being from two varieties of the same species, are very much alike 

 in all respects, but it seems from the slight differences in the reactions that one could with reason- 

 able certainty be distinguished from the other. 



GENUS ANTHOLYZA. 



This genus includes about 20 species of cormous plants, natives of the Cape of Good Hope and 

 tropical Africa. Some of them were introduced into cultivation about the middle of the eighteenth 

 century, and they are popularly known as African corn flag. The starches from A. crocosmoides 

 and A. paniculata were studied as types of the genus. 



Chart No. 287. 



P I GV T P 

 S 



CI CA PA FC f' S CI PA CA 



STARCH OF ANTHOLYZA CROCOSMOIDES. (Plate 73, figs. 437 and 438. Chart 287.) 



Histological Characteristics. Inform the grains are simple and isolated, with the exception of a 

 few aggregates in the form of doublets, triplets, and very rare quadruplets and quintuplets, and a few 

 clumps. Practically all of the isolated grains are marked by one or more pressure facets at the distal 

 end; these are usually large and sharply defined, but some large grains have a number of small, 

 often poorly defined facets at the distal end. The surface is usually regular, but in some cases one 

 side of the distal end is more prominent than the other, 

 especially if there are two or more facets of unequal size 

 present. The conspicuous forms are the spherical, hemi- 

 spherical, and rounded ovoid. The hemispherical forms 

 have from one to three or more pressure facets at the 

 base. The aggregates are almost invariably in the form 

 of doublets and triplets, the former being elliptical and 

 the latter rounded triangular, the junctions of the com- 

 ponents being indicated by linear depressions or fissures. 

 Among the smaller grains polygonal forms are common. 

 The grains are not flattened, and when seen on end ap- 

 pear spherical. There was considerable foreign matter 

 in the preparation which could not be removed. 



The hilum is a rather large round spot or cavity 

 which is generally distinct. It is usually eccentric about 

 two-fifths or less of the longitudinal axis and in some 

 small grains it is centric. It is sometimes fissured by a 

 short, straight, transverse fissure, or by three short, 

 straight fissures proceeding from a central cavity; or, 

 rarely, by a number of short, irregular fissures. 



The lamellce are usually indistinct, but when they can clearly be seen they appear as rather 

 coarse, regular, complete rings with the form of the outline of the grains, except near the hilum, 

 where they are circular. The number was not satisfactorily determined, but there are probably 

 5 to 7 on the larger grains. 



The grains vary in size; the smaller, round grains are 0.75/i; the larger are 24 by 28/i to 18 

 by 18/n in length and breadth. The common sizes are 12 by 10^ and 10 by lOfi in length and breadth. 



ill 



Curve of Reaction-Intensities of Starch of Antholyza 

 crocosmoides. 



