NER1NE. 



485 



The grains of this starch differ from those of N. 

 crispa, in having a larger number of components in the 

 compound grains, in the presence of aggregates, in being 

 more regular in form, in being somewhat narrower in 

 form, and in having the proximal end smaller than the 

 distal end in the majority of grains. 



The hilum is not so distinct as in N. crispa, and is 

 very much less apt to be fissured. When Assuring does 

 occur it takes the folio-wing forms: (1) A small straight 

 transverse or oblique line which may be branched; (2) 

 a small flying-bird. The hilum is eccentric from 0.42 

 to 0.17, usually 0.23, of the longitudinal axis, slightly 

 more than in N. crispa. 



The lamellce arc, as a rule, finer than those of N. 

 crispa and therefore not so distinct, and as a rule are not 

 so fine at the distal end as near the hilum, whereas in 

 N. crispa the number of grains in which they are not so 

 fine at the hilum as at the distal end about equals the 

 number of grains in which the reverse is true. There is 

 one very distinct, continuous, coarse lamella on nearly 

 every grain, as in iV. crisjm. The number counted on 

 the larger grains varies from 20 to 35, usually 30, some- 

 what less than in N. crispa. 



The size of the grains varies from the smaller which 

 are 4 by 4/n to the larger more slender elongated forms 

 which are 46 by 24/t, and the larger broader forms 46 

 by 30/i, in length and breadth. The common sizes are 

 30 by 20/x, and 30 by Zip. The sizes generally are less 

 than in N. crispa. 



Polamscopic Properties. 



The figure is slightly to very eccentric, usually some- 

 what more eccentric than in N. crispa, distinct and more 

 apt to be clear-cut than in N. crispa. The lines are 

 more often fine than in N. crispa and usually intersect 

 obliquely, and in fewer grains at right angles than in 

 N. crispa. They are more often straight than in N. 

 crispa, but are sometimes bent as in those grains and 

 very rarely bisected. Double figures are rare as in N. 

 crispa. 



The degree of polarization is moderate to very high 

 (value 80), less than in N. crispa. It varies in different 

 grains and fewer grains have a very high and high 

 polarization than in N. crispa. Occasionally, as in N. 

 crispa, moderate variation in polarization in the same 

 aspect of a given grain is present. 



With selenite the quadrants are usually well defined 

 and more unequal in size, but less irregular in shape 

 than in N. crispa. The colors are usually pure but are 

 not so often pure as in N. crispa, and the yellow is less 

 often pure than the blue. A very few of the grains have 

 a greenish tinge. 



Iodine Reactions. 



With 0.25 per cent Lugol's solution the grains color 

 a moderate blue with a tinge of violet (value 55), deeper 

 than in N. crispa, and the color becomes more rapidly 

 deep to very deep than in N. crispa. With 0.125 per 

 cent Lugol's solution the grains color a moderate to light 

 blue with somewhat more violet than in N. crispa, and the 

 color deepens somewhat more rapidly than in N. crispa 

 to a moderately deep to deep degree. After heating in 

 water until the grains are gelatinized, and then adding 

 a 2 per cent Lugol's solution, the grains are colored a 

 moderate to very deep indigo, not so deep as in N. crispa; 



tin' capsules are usually indistinguishable from the con- 

 tents; and the S'thtlioii color a deeper indigo blue than 

 in N. crispa. If tin- preparation is boiled for 2 minutes 

 and then treated with an excess of 2 per cent Lugol's 

 solution, the grain-residues color light to moderately 

 deep blue, less than in N. crispa, the capsules a pure 

 violet as in N. crispa, and the solution a deeper indigo- 

 blue than in N. crispa. 



Aniline Reactions. 



With gentian violet the grains color very lightly at 

 once, and in half an hour they are light to moderately 

 colored (value 35), lighter than in N. crispa. As in 

 -Y. crispa, some grains are more colored than others, 

 and many of the individual grains are more colored at the 

 distal end than elsewhere. 



With safranin the grains color very lightly at once, 

 and in half an hour they are moderately colored (value 

 45), but less than in N. crispa. As in N. crispa, some 

 grains are more colored than others, and many of the indi- 

 vidual grains are more colored at the distal end than 

 elsewhere. 



Temperature Reactions. 



The majority of the grains are gelatinized at 68.5° 

 to 70° C, and in all at 75° to 76.9° C, mean 75.9° C, 

 or 5.2° C. higher than in N. crispa. 



Effects of Various Reagents. 



The reaction with chloral hydrate begins immediately. 

 Complete gelatinization occurs in about 9 per cent of the 

 entire number of grains and 15 per cent of the total starch 

 in 5 minutes ; in about 84 per cent of the grains and 89 

 per cent of the total starch in 15 minutes ; in about 96 

 per cent of the grains and 97 per cent of the total starch 

 in 30 minutes. (Chart D 190.) 



The hilum as in N. crispa is distinct, and a bubble 

 is much less frequently formed there than in those grains. 

 The lamelte are not quite so distinct as in N. crispa. 

 A broad refractive band, which is much more refractive 

 than in N. crispa, is quickly formed about the margins 

 of the grains. Gelatinization begins usually at the proxi- 

 mal end and this may be quickly followed (but is usually 

 not) by gelatinization of the distal end, but in some 

 grains it begins first at the distal end, then at the proxi- 

 mal end, or it may begin at and continue only from the 

 distal end. Gelatinization progresses more smoothly 

 than in N. crispa with less invasion by fissures and sepa- 

 ration of gelatinized from ungelatinized starch, and 

 the most resistant portion is usually found much nearer 

 the distal margin, than in N. crispa. The gelatinized 

 grains are large and considerably distorted but not so 

 distorted as in N. crispa. 



The reaction with chromic acid begins in rare grains 

 immediately. Complete gelatinization occurs in much 

 less than 0.5 per cent of the entire number of grains and 

 total starch in 5 minutes; in still less than 0.5 per cent 

 of the grains and 3 per cent of the total starch in 15 

 minutes ; still in less than 0.5 per cent of the grains but 

 in 50 per cent of the total starch in 30 minutes ; in about 

 68 per cent of the grains and 92 per cent of the total 

 starch in 45 minutes; in more than 99 per cent of the 

 grains and total starch in 60 minutes. (Chart D 191.) 



The reaction with pyrogallic acid begins in rare 

 grains immediately. Complete gelatinization occurs in 



