GENUS TULIPA. 



533 



Chart No. 136. 



GV S T CI CA PA FC P S CI PA CA 

 POPS 



5 I 



Curve of Reaction-Intensities of Starch of Tulipa clusiana. 



and the distal end. The hunolla' arc not clearly tlenionstrable over the entire grain, and as many 

 as 38 to 40 lamella; may be found on the larger grains. 



The size of the smaller, round grains is 2 by 2ju; the larger, broader grains are 50 by iO/x; the 

 narrower grains are 50 by 25;u in length and breadth. The common size of the narrow forms is 

 30 by IG/i and of the broader grains 34 by 30/i in length and breadth. 



Polariscopic Properties. The figure is usually eccentric. It is distinct and fairly clear-cut. 

 The lines of the figure are rather thick, generally straight, and expanded at the distal and proximal 

 margins. They are occasionally bent and rarely bisected. The figure is the same as in T. hageri. 



The degree of polarization is fairly high. There is considerable variation in the different grains 

 and in the same aspect of the same grain. It is higher 

 than in the grains of T. hageri. 



With selenite the quadrants arc fairly well defined, 

 usually regular in shape, and miequal in size. The blue is 

 quite pure, and the yellow is fairly pure, as in T. hageri. 



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

 tion the grains color a deep blue-violet; with 0.125 per 

 cent solution they color fairly and the color deepens rap- 

 idly. It is not quite so deep as that of the grains of T. 

 hageri. After heating in water until all the grains are com- 

 pletely gelatinized, the solution colors somewhat deeply 

 and the swollen grains deeply on the addition of iodine. 

 After boiling for 2 minutes the solution colors very deeply 

 and the grain-residues very lightly or not at all. The cap- 

 sules are all colored a red-violet with an excess of iodine. 



Stainitig Reactions. With gentian violet the grains 

 begin to stain at once and in 30 minutes they are 

 stained fairly. The stain is slightly more than that of 

 the grains of T. hageri. 



With safranin the grains begin to stain at once and 

 in 30 minutes they are lightly stained. The stain is more than that of the grains of T. hageri. 



Temperature Reaction. The temperature of gelatinization is 54 to 55.7 C, mean 54.85. 



Effects of Various Reagents. With chloral hydrate-iodine the reaction begins in all in 15 sec- 

 onds. It is over in nearly all in 4 minutes and in all in 6 minutes. It is the same qualitatively as 

 that of the grains of T. hageri. 



Reaction with chromic acid begins at once and is over in 40 seconds. It is the same qualita- 

 tively as that of the grains of T. hageri. 



The reaction with pyrogallic add liegins in a very few seconds and is over in 50 seconds. It 

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



With ferric chloride reaction begins in a few grains in 15 seconds. It is over in nearly all in 

 3 minutes and in all in 4 minutes. It is the same qualitatively as that of the grains of T. hageri. 



Reaction ^^-ith Purdy's solution begins in a very few seconds and is over in a minute. It is 

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



STARCH OF TULIPA CLUSIANA VAR. PERSICA. (Plate 33, figs. 197 and 198. Chart 137.) 



Histological Characteristics. In form the grains are simple and isolated, except in case of a few 

 doublets. There are no pressiu-e facets. The surface is quite regular, more so than in T. clusiana. 

 The conspicuous forms in the larger grains are triangular with rounded angles and curved base, 

 somewhat clam-shell-shaped, and pjTiform. The smaller grains are pyriform, oval, flattened 

 ellipsoidal, and round. The grains are flattened, and when viewed on edge they frequently appear 

 narrower at the distal end. 



The hilum is a round, fairly refractive spot with a range of eccentricity from one-fourth to 

 one-sixth, usually one-fifth, of the longitudinal axis. A short transverse fissure may be found at 

 the hilum. 



The lamellae are mostly fine, but a few are quite coarse. When demonstrable near the hilum 

 they form complete circles, but those near the margin and the distal end have the form of the outline 

 of the grain and may be incomplete. In the large grains there are usually one to three or more 



