GENUS LEUCOIUM. 



653 



often bordered by a layer of regularly arranged granules and four or five ungelatinized lamelliE. 

 Most of these granules soon become gelatinized, but frequently a few are found when examined 

 even after an hour. In some of the grains delicate fissures do not form at the region of the hilum, 

 but the clefts deepen and break the starch into a few large granules which gradually gelatinize. The 

 gelatinized grains are somewhat swollen, but retain the general shape of the untreated grain. 



STARCH OF LEUCOIUM VERNUM. (Plate 56, figs. 331 and 332. Chart 221.) 



Histological Characteristics. — In form the grains are almost wholly simple and are isolated, 

 except a few which occur in small aggregates and clumps. Pressure facets are occasionally observed. 

 There are a few compound grains. The general characteristics of the forms of the grains are the 

 same as those found in L. cestivum. 



The hilu7n is usually eccentric about one-third to one-fourth of the longitudinal axis. It may 

 be observed as a clear round or lenticular spot, but generally it is fissured. The arrangement and 

 character of the clefts is the same as that noted for L. cestivum. 



The lamellae are not distinct, except one that is very refractive and located at varying distance 

 from the hilum. They are not usually demonstrable near the hilum and also frequently at the distal 

 end. In many of the medium-sized grains 28 lamellae can be counted. The lamellae are of the same 

 character and shape as those noted for L. cestivum, but on the whole less indistinct. 



The grains vary in size; the smaller are 4 by 2;u; the 

 larger, broadened forms are 46 by 50fi, and the elongated 

 are 60 by 46;Lt in length and breadth. The grains of 

 common size are about 30 by 36m in length and breadth. 



Polariscopic Properties. — The figure is usually eccen- 

 tric. Its lines are of the same character and arrangement 

 as in L. cestivum. Double and multiple figures, the same 

 as those of L. cestivum, are observed. 



The degree of polarization is high, but slightly lower 

 than in L. cestivum. It ranges from fair to very high. 

 The variation in the same aspect of a grain is the same 

 .as in L. cestivum. 



With selenite the character of the quadrants and the 

 colors are the same as in L. cestivum. 



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

 tion the grains color a rather deep violet with a reddish 

 tint, the colors deepening rather rapidly. The tint is 

 slightly redder, and slightly less, and it does not deepen 

 quite so rapidly as in L. cestivum. With 0.125 per cent 

 solution they color a rather light violet, slightly deeper 

 than in L. cestivum. After heating the grains in water until all are completely gelatinized and then 

 adding iodine, the solution becomes a deep indigo-blue and the grains a fairly deep blue. If the 

 grains are boiled for 2 minutes and then treated with iodine, the solution colors a very deep blue, and 

 the grain-residues generally a light blue, on the whole lighter than in L. cestivum. The capsules are 

 colored a light reddish-violet. With an excess of iodine the capsules become old-rose to wine-red. 

 The tint is slightly redder and brighter than in L. cestivum. 



Staining Reactions. — With gentian violet the grains color very slightly at once and in 30 minutes 

 are very lightly colored. The tint is about the same as in L. cestivum. 



With safranin the grains begin to stain slightly at once and in 30 minutes are lightly colored. 

 The tint is about the same as in L. cestivum. 



Temperature Reaction. — The temperature of gelatinization is 71° to 72° C, mean 71.5°. 



Effects of Various Reagents. — With chloral hydrate-iodine reaction begins immediately. Many 

 of the smaller grains and a few of the larger are gelatinized in 2 minutes, about three-fifths in 5 

 minutes, four-fifths in 15 minutes, and nearly all in 30 minutes. Rare resistant grains may last 60 

 minutes. The reaction is qualitatively the same as in L. cestivum. 



Reaction with chromic acid begins immediately. A few grains are dissolved in a minute and 

 nearly all in 4 minutes. The most resistant grains are usually dissolved in from 7 to 9 minutes. 

 The reaction is qualitatively the same as in L. cestivum. 



Curve of Reaction-Intensities of Starch of 

 Leucoium vernum. 



