558 



STARCHES OF LILIACEiE. 



PS CI PA CA 

 PCPS 



end than near the hilum and do not vary much in size and distinctness in different grains. There 

 are about 8 to 12 on the larger grains. 



The grains vary in size from 5 to 40ju. The common size is 24;u. 



Polariscopic Properties. — The figure is usually eccentric, distinct, usually fairly clear-cut, and 

 rather irregular. As a rule the lines are not thick, but they sometimes become thicker and less 

 clear-cut at the margin. They ai-e oft«n bent and bisected, and sometimes placed at varying angles 

 with one another. The lines are much more irregular than in 0. nutans and 0. umbellatum. 



The degree of polarization is high. It does not vary much in different grains or in different 

 aspects of the same grain, but is sometimes low in some parts near the margin of the same aspect of 

 a given grain. It is not quite so high as in 0. nutans. 



With selenite the quadrants, as a rule, are fairly well 

 defined, quite irregular in shape, and unequal in size. The 

 colors are usually pure. 



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

 tion the grains color a fairly deep blue-violet; with 0.125 

 per cent solution they color rather lightly and the color 

 deepens fairly rapidly. The color is slightly less than that 

 of the grains of 0. nutans. After heating in water until 

 all the grains are completely gelatinized, the solution 

 colors fairly and the grains deeply on the addition of 

 iodine. After boiling for 2 minutes the solution is colored 

 deeply and the grain-residues fairly. The capsules are 

 colored reddish-violet when an excess of iodine is added, 

 and most of them retain more or less blue-reacting starch. 



Staining Reactions. — ^With gentian violet and with saf- 

 ranin the grains begin to stain at once and in 30 min- 

 utes they are fairly deeply stained, but not so deeply as 

 the grains of 0. nutans. 



Temperature Reaction. — The temperatm-e of gelatin- 

 ization is 55° to 56° C, mean 55.5°. 



Effects of Various Reagents. — ^With chloral hydrate-iodine the reaction begins in 30 seconds. 

 It is over in most grains in 4 minutes and in all in 6 minutes. It is the same qualitatively as that 

 of the grains of 0. nutans. 



Reaction with chromic add begins at once and is over in 20 seconds. It is the same quahta- 

 tively as that of the grains of 0. nutans. 



Reaction with pyrogallic acid begins in 30 seconds and is over in 2 minutes. It is the same 

 quaUtatively as that of the grains of 0. nutans. 



With ferric chloride reaction begins in some grains in 30 seconds and is over in 10 minutes. 

 It is qualitatively the same as that of the grains of 0. nutans. 



The reaction with Purdy's solution begins at once. It is over in almost all the grains in 30 seconds 

 and in all in IJ^ minutes. It is the same qualitatively as that of the grains of 0. nutans. 



STARCH OF ORNITHOGALUM THYRSOIDES VAR. AUREUM. 

 (Plate 38, figs. 227 and 228. Chart 152). 



Histological Characteristics. — In form the grains are simple. There are some doublets, multi- 

 ples, and clumps. No pressure facets were observed. The surface of the grains is often quite irreg- 

 ular and somewhat varied, owing in minor part to a few irregular depressions, and in major part 

 to lamellated additions (of varying size) to the sides or to the distal end. The longitudinal axes 

 of these additions form angles with the longitudinal axes of the grains. The conspicuous forms are 

 elongated ovoid to rounded ovoid; also spherical, quadrangular with rounded proximal end, tri- 

 angular with rounded angles, and a few lenticular forms, and various irregular forms. These grains, 

 Uke those of 0. narbonense (jpyramidale) , are distinctly more irregular than those of 0. nutans and 

 0. umbeUatum. The grains are not flattened and are as thick as they are wide. 



ITie hilum is not very distinct, and is a small round spot. It is usually eccentric about one- 

 fourth, less often one-third, of the longitudinal axis, and in or near the median line; sometimes 

 2 or more hila appear in a single grain. Occasionally the hilum is fissured, when there is usually 



Curve of Reaction-Intensities of Starch of Ornithogalum 

 narbonense (pyramidale). 



