GENUS LILIUM. 



475 



Polariscopic Properties. The figure is vory eccentric and distinct, but the lines are not 

 clear-cut. The lines are usuallj' broad, anil broaden and become more diffused as they are 

 nearer the mai-gin of the grain. They often vary in width along their course, sometimes being 

 bent and occasionally bisected or divided into branched lines. The angle of intersection of the 

 lines also varies. 



The degree of polarization is high, not varying much in different grains, but varying in different 

 aspects of the same grain, being higher when the grain is viewed on end or on edge. In the same 

 aspect of a grain it is usuallj' not so high near the distal entl as near the hilum. 



With selenite the quadrants are not sharply defined and are somewhat irregular in shape and 

 unequal in size. The colors are usually not pure. 



Iodine Reactions. With 0.25 per cent Lugol's solution the grains color a deep blue-violet, 

 deeper at the margin and distal end than elsewhere; with 0.125 per cent solution they color fairly 

 deeply, and the color ileepens rapidly. After heating in water until all the grains are completely 

 gelatinized, both the solution and the swollen grains color 

 deeply on the addition of iodine. After boiling for 2 min- 

 utes the solution colors very deeply and the grain-resi- 

 dues not at all or lightly. With an excess of iodine the 

 capsules all color a red-violet. 



Staining Reactions. With gentian violet and with 

 safranin the grains begin to stain at once and after 30 

 minutes they are stained rather light. 



Temperature Reaction. The temperature of gelatin- 

 ization is 61.2 to 62.1 C, mean 61.65. 



Effects of Various Reagents. With chloral hydrate- 

 iodine the grains begin to react at once. Almost all are 

 gelatinized in 10 minutes and all in 15 minutes. The entire 

 grain is immediately colored an old-rose. As the grain 

 swells, either clouds or strands of darker color stream 

 from the distal end towards the proximal end, at which 

 a knob-like protuberance is formed that is stained a deep 

 indigo-blue. A mass of substance so stained now appears 

 at the distal end, and sometimes a thin layer of color also 

 appears along the lateral margin. These two, with or 

 without additional colored masses, now approach each other, pushing before them a thin, colorless 

 envelope which forms a line of demarcation between the gelatinized and non-gelatinized parts. The 

 central portion of the grain is the last to undergo gelatinization. Sometimes gelatinization is coinci- 

 dent at the proximal and distal ends, the latter end then being usually quite irregular in outline. In 

 the broadly triangular or shell-shaped forms two protuberances frequently appear at the corners limit- 

 ing the distal margin, then similar formations at the proximal end, and gelatinization advances from 

 these points around the entire margin and towards the center, which is finally gelatinized. Sometimes 

 a dark ring appears at the hilum, which breaks and forms a U, and is obscured as the colored, gelat- 

 inized part of the grain advances. At other times a transverse dark line appears at the hilum, 

 which is drawn into a triangle and then obscured by the blue, proximal mass. The gelatinized 

 grains are uniformly dark, except a light area which is probably the swollen hilum. Light, trans- 

 verse lines at irregular intervals and two oblique lines extending from the position of the hilum 

 towards the distal end may be observed. While the gelatinized grain is much enlarged and some- 

 what irregular in outline, it retains the general shape of the untreated grains. 



Reaction with chromic acid begins at once and is complete in 50 seconds. The hilum becomes 

 very distinct as a small light spot and two refractive lines pass from it towards the corners of the 

 distal margin. The lamellae at the distal margin are very distinct and finely striated. The proximal 

 end swells rapidly, the clear space is enlarged at the hilum, and fine lines pass out from the two 

 main lines mentioned above and also from the base of the gelatinized center of the grain. The entire 

 grain is much enlarged and the outer layer at the proximal enil becomes ruptured and allows the 

 inner, gelatinized starch to flow out. The striated lamellaj at the distal margin are the last to be 

 dissolved. During the process of solution a bubble is sometimes formed at the hilum, which pre- 

 cedes the formation of a channel of solution through the grain and finally collapses near the hilum end. 



Curve of Reaction-Intensities of Starch of LilJum 

 candidum. 



