IRIS. 



641 



The hilum is more distinct than in I. iberica and is 

 much more frequently fissured than in those grains and 

 the fissures take the following forms: (1) Large flying- 

 bird; (2) straight, transverse line, sometimes branched; 

 (3)2 fissures forming an angle. Not infrequently when 

 the hilum is fissured by a straight transverse fissure, 2 

 refractive fissures, as in I. iberica, are seen in the interior 

 of the grain extending from the hilum distally. The 

 hilum is eccentric from 0.24 to 0.1, usually 0.1S, of the 

 longitudinal axis, and is less eccentric than that of 

 7. iberica. 



The lamella! are coarser and more distinct than in 

 I. iberica. Near the hilum they are circular in form 

 and continuous, and in the rest of the grain they appear 

 to be discontinuous and to follow the form of the outline 

 of the grain. They are more apt to be irregular than in 

 7. iberica, and the irregularity is most conspicuous mid- 

 way between the hilum and margin, and follows and 

 emphasizes the form of the notch in the distal margin. 

 The lamellae near the distal end are usually coarser than 

 those near the hilum, and there is frequently a very 

 refractive, coarse, continuous lamella midway between 

 the hilum and margin, and less often 2 or 3 such lamellae 

 dividing the rest of the lamellae into groups of varying 

 size. The number of lamellae counted on the larger 

 grains varies from 14 to 22, usually 16, and more than in 

 I. trojana. 



In size the grains vary from the smaller which are 

 5 by 5/i, to the larger which are 48 by 22/i, in length 

 and breadth. The common sizes are 28 by 20/i and 30 by 

 14/i. The common sizes are 8/i longer and 6/i broader, 

 and lO/i longer and no narrower, than the common sizes 

 of 7. iberica. 



Polariscopic Properties. 



The figure is distinct and somewhat less well defined 

 than in I. iberica. The lines cross at a more acute angle 

 which varies much less in size in different grains than in 

 7. iberica. They are more often bent than in I. iberica 

 but rarely bisected as in that starch. 



The degree of polarization varies from low to moder- 

 ately high (value 45), 5 units less than in I. iberica. 

 There is usually some variation in a given aspect of a 

 grain. It is usually lower in the area between the two 

 arms of the cross than elsewhere. 



With selenite the quadrants are not quite so well 

 defined as in either parent. They are usually somewhat 

 more unequal in size and irregular in shape than in 

 7. iberica. The colors are usually somewhat less pure 

 than in 7. iberica. 



Iodine Reactions. 



With 0.25 per cent Lugol's solution the grains all 

 color a moderate violet tinged with blue (value 50), 

 10 units more than in 7. iberica. The color has more 

 of a bluish tint than in 7. iberica, and deepens more 

 rapidly until it is very deep and has assumed still more 

 of a bluish tint. With 0.125 per cent Lugol's solution 

 the grains all color a light to moderate violet tinged 

 with blue, more than in 7. iberica. The color as in 

 7. iberica deepens rapidly until it is deep and has assumed 

 more of a bluish tint. After heating in water until all 

 the grains are completely gelatinized and then treating 

 with a 2 per cent Lugol's solution, the gelatinized grains 

 all color a moderately deep or deep indigo, less than in 



7. iberica, and the solution a deep indigo, more than in 

 /. iberica. If the preparation is boiled for 2 minutes 

 and then treated with an excess of iodine, more grain- 

 residues than in 7. iberica are colored a light indigo; 

 the capsules, a wine-red or a violet, which is not so deep 

 as in 7. iberica; and the solution colors a very deep indigo, 



as in 7. iberica. 



Aniline Reactions. 



With gentian violet the grains, as in 7. iberica, stain 

 very lightly at once, and in 30 minutes they are moder- 

 ately stained (value 50), 10 units more than in 7. iberica. 

 There are a few grains which are deeply, the rest are 

 moderately, or light to moderately, stained. 



With safranm the grains, as in 7. iberica, stain very 

 lightly at once, and in 30 minutes they are moderately 

 stained (value 50), 5 units more than in 7. iberica. 

 The staining is the same as with gentian violet. 



Temperature Reactions. 



The temperature of gelatinization of the majority 

 of the grains is 70° to 71.5° C, and of all 73.2° to 

 75° C, mean 74.1° C. This is 2.3° C. higher than that 

 of 7. iberica. 



Effects of Various Reagents. 



The reaction with chloral hydrate begins in 1 minute. 

 Complete gelatinization occurs in about 6 per cent of the 

 entire number of grains and 18 per cent of the total 

 starch in 5 minutes; in about 35 per cent of the grains 

 and 51 per cent of the total starch in 15 minutes; in 

 about 62 per cent of the grains and 77 per cent of the 

 total starch in 30 minutes; in about 77 per cent of the 

 grains and 88 per cent of the total starch in 45 minutes ; 

 in about 84 per cent of the grains and 93 per cent of 

 the total starch in 60 minutes. (Chart D 379.) 



The hilum becomes distinct as in 7. iberica, attended 

 by the formation of a bubble in fewer grains than in that 

 starch. The lamellae are at first more distinct but become 

 obliterated during the course of the reaction as in 

 7. iberica. The grain becomes more refractive, the first 

 part to show this change is a rather narrow band at 

 the margin which is narrower and more refractive 

 than a similar band in 7. iberica. Gelatinization begins 

 in the same manner as in 7. iberica at the corners of the 

 distal margin and the progress of gelatinization is similar 

 to that described under 7. iberica, except that the 2 inter- 

 nal fissures which extend longitudinally on either side are 

 more prominent in these grains and extend around the 

 hilum, thus completely separating the marginal from the 

 central part of the grain, and either may be gelatinized 

 first. In more grains than in 7. iberica, where gelatiniza- 

 tion has progressed about halfway from the distal end 

 to the hilum, the proximal starch may be gelatinized and 

 the two processes approach one another, the most resistant 

 portion being just distal to the hilum. 



The gelatinized grains are as much swollen, have as 

 thin capsules, and are as distorted as in 7. iberica. 



The reaction with chromic acid begins in 30 sec- 

 onds. Complete gelatinization occurs in about 5 per cent 

 of the entire number of grains and 29 per cent of the 

 total starch in 5 minutes; in about 37 per cent of the 

 grains and 90 per cent of the total starch in 15 minutes; 

 in about 75 per cent of the grains and 98 per cent of the 

 total starch in 30 minutes; in about 95 per cent of the 

 grains and in more than 99 per cent of the total starch 



