GENUS ORNITHOGALUM. 



559 



Chart No. 152. 



GV S T CI CA PA FC P S CI. PA CA 



but one .shurt, iian-uw, clean-cut, transveise or diasoual fi.ssiirc, straij;lit or curved; or there luay be 

 two short, narrow, straight clean-cut fissures forming a cross. 



The lamcUce are distinct, rather coarse, irregular rings, continuous near the hilum, but probably 

 discontinuous near the distal end. They are coarser and more ilistinct near the distal end than near 

 the hilum, and varj' in size and distinctness in different grains. There are 12 to 14 on the larger grains. 



The grains vary in size from 4 to 44ju. Tlie common size is 27ai. 



Polariscopic Properties. The figure is eccentric, distinct, usuallj' fairly clear-cut, and irregular. 

 Its lines are rather thin, but often become thicker and less well defined near the margin, and often 

 are very much bent and otherwise distorted, and some- 

 times bisected. They are at variable angles to each other. 



The degree of polarization is high. It varies in different 

 grains and in different parts of the same aspect of a grain. 

 It is shghtly higher than that of the grains of 0. nutans. 



With selcniie the quadrants are fairly well defined, 

 but usually very irregular in shape and unequal in size. 

 The colors are generally pure. 



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

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

 0.125 per cent solution they are colored rather lightly 

 and the color does not deepen rapidly. The color is less 

 than that of the grains of 0. nutans. After heating in 

 water until all of the grains are completely gelatinized, 

 the solution colors rather lightly and the grains very 

 deeply on the addition of iodine. After boiling for 2 

 minutes the solution colors deeply and the grain-residues 

 hghtly or not at all. With excess of iodine the capsules 

 color a reddish-violet, and most of them retain more or 

 less blue-reacting starch. 



Staining Reactions. With gentian violet and with safranin the grains begin to stain at once 

 and in 30 minutes they are deeply stained. The color is not quite so deep as that of 0. nutans. 



Temperature Reaction. The temperature of gelatinization is 65 to 67 C, mean 06. 



Effects of Various Reagents. With chloral hydrate-iodine the reaction begins in 15 seconds 

 and is over in 5 minutes. It is the same qualitatively as that of the grains of 0. nutans. 



Reaction with chromic acid begins in 15 seconds and is over in 2 minutes. It is the same quali- 

 tatively as that of the grains of 0. nutans. 



The reaction with ptjrogallic acid begins at once and gelatinization is complete in IJ^ minutes. 

 The reaction is qualitatively the same as that of the grains of 0. nutans. 



Reaction with ferric chloride begins in a few grains in 45 seconds and is over in 14 minutes. 

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



With Purdy's solution the reaction begins in a few grains in a very few seconds and is over in 

 a minute. In the rest of the grains it begins in a minute and is over in most of them in 4 minutes, 

 and in all in 10 minutes. It is the same qualitatively as that of the grains of 0. nutans. 



Curve of Reaction-Intensities of Starcli of Ornithogalum 

 thyrsoides var. aureum. 



Differentiation of Certain Starches of the Genus Ornithogalum. 



Histological Characteristics. 

 Con.si)icuous Forma. 



(). itidnns: Simi)le, lare doublets, surface somewhat Lri-cg- 

 ular, no pressure facets, secondary deposits of 

 lamellae. Rounded ovoid, and ovoid with a narrow 

 .squared distal end with a small depression. 



O. umhellatum: Generally essentially the same as in 0. 

 nutans except slightly more irregularities of sur- 

 face and greater conspieuousness of the ovoid 

 grains with modified distal end. 



O. narbonense (pi/ramidale): Essentially the same as in 

 0. U7nbellatum, excepting a much greater irregular- 

 ity of the grains. 



Histological Characteristics. Continued. 



Conspicuous Forms Continued. 

 0. thyrsoides var. aureum: Essentially the same as in O. 

 nutans except that the elongated ovoid are very 

 prominent, and the surface of grains decidedly more 

 irregular. 



Hilum Form, Number, and Position. 



0. 7iutans: Form fairly distinct, small to comparatively 

 large, round or rarely lenticular spot; usually 

 single; sometimes fissured, fissure usually small, 

 single, and clean-cut, or may be a cross or stellate 

 arrangement. Position eccentric about 0.33 of 

 the longitudinal axis or centric. 



