GENUS TULIPA. 



529 



With selcnite the quadrants are fairly well defined, ordinarily regular in shape, and unequal in 

 size. The blue is pure, the yellow not quite pure, as in T. hageri. 



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

 with 0.125 per cent solution the}- color fairly and the color deepens rapidly. It is not quite so deep 

 as that of the grains of T. hageri. After heating in water until all the grains are completely gelatinized, 

 the solution colors fairly deeplj' and the swollen grains deeply on the addition of iodine. After 

 boiling for 2 minutes the solution colors very deeply and the grain-residues lightly. The capsules 

 all color a red-violet with a slight excess of iodine. 



Staining Reactions. With gentian violet the grains begin to stain very lightly at once and in 

 30 minutes they are fairly stained, some more than others. The stain is slightly more than that 

 of the grains of T. hageri. 



Safranin. The grains begin to stain very lightly at once, and in 30 minutes they are lightly 

 stained, some more than others. The stain is slightly more than that of the grains of T. hageri. 



Temperature Reaction. The temperature of gelatinization is 55.1 to 55.4 C, mean 55.25. 



Effects of Various Reagents. With chloral hydrate-iodine reaction begins in some grains in 15 

 seconds, in all in 30 seconds. It is complete in nearly all in 10 minutes and in all in 15 minutes. 

 It is the same qualitatively as that of the grains of T. hageri. 



With chromic acid the reaction begins in a few seconds and is over in 45 seconds. It is the 

 same quaUtatively as that of the grains of T. hageri. 



The reaction with pyrogallic acid begins in some grains in a few seconds and is over in 2J^ 

 minutes. It is the same qualitatively as that of the grains of T. hageri. 



Reaction with ferric chloride begins in a few grains in 15 seconds. It is over in nearly all in 5 

 minutes and all in 7 minutes. It is the same qualitatively as that of the grains of T. hageri. 



The reaction with Purdy's solution begins in a few seconds and is over in 3 minutes. It is the 

 same qualitatively as that of the grains of T. hageri. 



STARCH OF TULIPA DIDIERI. (Plate 32, figa. 189 and 190. Chart 133.) 



Histological Characteristics. In form the grains are simple and nearly always isolated. There 

 are no pressure facets. The surface is usually regular. Some irregularities are caused by protuber- 

 ances near or at the proximal end, of the kind noted under T. hageri. The conspicuous forms among 

 the larger grains are triangular with rounded angles and 

 base to clam-shell-shaped and pyriform. Among the large 

 grains there are flattened pyriform approaching a bottle 

 shape, and a few resembling the form of the Indian flint 

 arrow-head. Among the smallest grains are slightly flat- 

 tened ellipsoidal, pyriform, ovoid, and round. The grains 

 are flattened, and when viewed on edge they are fre- 

 quently seen to be narrower at the distal end. There is 

 a larger proportion of grains with irregular outline than 

 in T. hageri. 



The hilum is a distinct, round, refractive spot, with 

 a range of eccentricity of one-fifth to one-eighth, usually 

 one-sixth, of the long axis. A transverse fissure is often 

 found at the hilum. 



The lamellce are mostly fine and indistinct, and when 

 demonstrable they form complete rings around the hilum, 

 and have the shape of the grain, appearing incomplete 

 towards the sides and distal end. There is often a band 

 of rather coarse, refractive lamella; at about three-fourths 

 of the distance between the hilum and the distal end, and 



the lamellse for the last one-fourth of the distance between these points may be coarser and more 

 refractive than those near the hilum. The larger forms apparently have about 27 or 30 lamellae, but 

 on account of the indistinctness the number can not be definitely determined. 



The size of the small grains is 4 by 4;*; the larger, broadened grains are 42 by 44;u; the elongated 

 grains are 50 by 42^ in length and breadth. The common size of the larger grains is 32 by 24/i in 

 length and breadth. 



Chart No. 133. 



Curve of Reaction-Intensitiea of Starch of Tulipa 

 didieri. 



