600 



STARCHES OF LILIACE^. 



QartNo. 179. 



PS CI PA CA 

 ■~ PC PS 



reactiou. About two-thirds are almost completely gelatinized in 20 minutes and all in 45 minutes. 

 The reaction is qualitatively the same as that of the grains of B. peduncularis. 



A few grains begin to react with ferric chloride in 30 seconds, about one-fourth are gelatin- 

 ous in 5 minutes, the rest are unaffected. About half are gelatinous or partially gelatinous in 10 

 minutes, two-thirds in 15 minutes, three-fourths in 30 minutes, and five-sixths in an hour. The 

 reaction is qualitatively the same as that of the grains of B. peduncularis. 



With Purdy's solution a few grains begin to react immediately. About one-fourth are affected 

 in 2 minutes, and some of them, including a good many of the smaller grains, are completely gelat- 

 inized. About half are affected and some of these completely gelatinized in 10 minutes, and two- 

 thirds are affected in 30 minutes, but the reaction is not complete in an hour. The reaction is the 

 same qualitatively as that of the grains of B. peduncularis. 



STARCH OF BRODI^^A PURDYI. (Plate 47, figs. 281 and 282. Chart 179.) 



Histological Characteristics. — In form the grains are simple, except a few compounds consisting 

 of two or three components that are often partially separated by fissures. Occasionally the smaller 

 grains form small aggregates, and grains of all sizes are found to some extent in large clumps. The 

 surface is, on the whole, fairly regular. There may be rounded projections of amorphous substance, 

 and also nipple-like processes. The conspicuous forms are the ovoid to nearly round, oval, and 

 ellipsoidal; also quadrangular with rounded corners, rarely pyriform, and many irregular forms. 

 The grains are not quite so thick as broad. 



When the hilum is not fissured it appears as a not very distinct, fairly large, round spot, which 

 conmionly is eccentric about one-fourth of the longitudinal axis of the grain. Double or triple hila 

 occur rarely, closely grouped in an amorphous, non-lamel- 

 lated space. Usually the hilum is fissured and the fis- 

 sures are commonly shallow and narrow. The fissm-e is 

 often simple, diagonal or transverse, clear-cut or ragged. 

 In some grains the hilum is not fissured, but the surface 

 of the grain is slightly fissured between the hilum and the 

 distal end. 



The lamelloe are regular, coarse rings, but as a rule 

 quite indistinct. Usually there is one distinct lamella 

 near the hilum. The lamellae follow closely the outline of 

 the margin, but are not distinct enough to count. 



The grains vary in size from 3 to 5ifi. The common 

 size is 26/t. 



Polariscopic Properties. — The figure is eccentric, dis- 

 tinct, but not clear-cut. Its lines are apt to become 

 broadest but less sharp near the margin, and also occa- 

 sionally in other parts of the grain. Sometimes a line 

 will be bisected, and sometimes they are slightly bent or 

 otherwise distorted. 



The degree of polarization is high. It is about the 

 same as that of the grains of B. peduncularis. It is absent from some parts of some of the grains, and 

 usually highest when the grain is viewed from the side or end. It varies somewhat in different grains. 



With selenite the quadrants are not usually well defined, and are generally irregular in shape 

 and unequal in size. The colors are fairly pure, especially the blue. 



Iodine Reactions. — With 0.25 per cent Lugol's solution the grains are colored deeply a blue- 

 violet, and the color gradually becomes deeper than in B. peduncularis; with 0.125 per cent solution 

 the grains color fairly and somewhat more than those of B. peduncularis. After heating until the 

 grains are completely gelatinized, the solution is colored fairly well and the grains very deeply with 

 iodine. In some grains, which are less deeply stained, a violet outer layer appears at the distal end. 

 After boiUng for 2 minutes the solution is colored more deeply, but the grain-residues much less 

 deeply. With a very slight excess of iodine all the capsules become violet. Most of the capsules 

 still contain blue-reacting starch in their proximal ends. 



Staining Reactions. — With gentian violet the grains begin to stain at once and after 30 minutes 

 are fairly deeply stained, much more than B. peduncularis. 



Curve of Reacdon-Intenaities of Starch of Brodiaea 

 purdyi. 



