GENUS TULIPA. 



525 



P I GV I P 



aariNo. 129, 



C V S T 



CI CAPAFC P3 CI PA CA 

 ' ' ' PC PS 



Curve of Reaction-Intensities of Starch of Tulipa 

 hageri. 



With selenite the quadrants are fairly well defined, fairly regular in shape, and unequal in size. 

 The blue is quite pure, while the yellow is moderately pure. 



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

 with 0.125 per cent solution they color quite well and the color deepens rapidly. After heating 

 in water until all the grains are completely gelatinized, the solution colors rather deeply and the 

 swollen grains deeply on the addition of iodine. After 

 boiling for 2 minutes the solution colors very deeply, but 

 the grain-residues rather 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 in about 30 seconds, and in 

 30 minutes they are fairly colored, some slightly more 

 than others. 



With safranin the grains begin to stain very lightly 

 in about 30 seconds, and in 30 minutes they are lightly 

 colored, some slightly more than others. 



Temperature Reaction. The temperature of gelatin- 

 ization is 50.4 to 51.4 C, mean 50.9. 



Effects of Various Reagents. With chloral hydrate- 

 iodine the reaction begins in many grains in 15 seconds 

 and is over in 9 minutes. The reaction starts at the proxi- 

 mal end, which first darkens and then swells out in the 

 form of a narrow, rounded projection, this being accom- 

 panied by the swelling of the hilum. At the hilum a 

 bubble meanwhile forms, which increases and then de- 

 creases in size as the hilum swells. The distal end in the meanwhile usually darkens and then the 

 sides of the grain, and the process of gelatinization and swelling moves inward from all sides, but more 

 rapidly from the proximal end, until finally all of the grain is gelatinized. At times the distal end 

 remains unaffected until the last. The swollen grains are fairly large, smooth, and not distorted; 

 they retain much of the original form. They are of a uniform dark color, except at the proximal 

 end, where there is a small, round, fight space. 



The reaction \vith chro7nic acid begins at once in most grains and is over in 45 seconds. It is 

 impossible to determine accurately all the steps of the reaction, but in the main they are as follows: 

 A bubble appears at the hilum and the grain becomes finely striated. The bubble increases in 

 size as the hilum and the proximal end of the grain swell out into a long, rounded projection, and 

 then decreases and disappears. Two lines or fissures extend from each side of the swollen grain 

 towards the sides of the distal end, and the starch between them is divided by a number of 

 longitudinal fissures into a granular mass which is pushed down to the distal end as the grain swells. 

 The margin of the swollen proximal end is dissolved and the granular material within the capsule 

 flows out and is dissolved and the remainder of the marginal starch at the sides and distal end 

 dissolves later. 



The reaction with pyrogallic acid begins in a very few seconds and is over in 1}^ minutes. The 

 hilum swells and a bubble appears which increases in size, enlarging principally in the direction of 

 the distal end, and the proximal end becomes invaginated. Two lines or fissures extend from each 

 side of the hilum towards the distal end, and the starch between them becomes divided by fine, 

 longitudinal stria or fissures. This part of the grain grows finely granular and collects at the distal 

 end as the grain swells. The invaginated proximal end usually straightens out gradually as the 

 grain swells. There is but little resistant starch at the margin, and what does appear there is soon 

 gelatinized and appears as a thin, transparent capsule. The swollen grains are large, smooth, and 

 not distorted at the proximal end, but wrinkled and sacculated at the distal end. They retain some 

 of the original form of the grain. 



With ferric chloride the reaction begins in a few grains in a few seconds and in all in 5 seconds; 

 it is over in nearly all in 3 minutes and in all in 5 minutes. The hilum swells, and also the starch 

 at the proximal end, to form a long, rounded projection from the pro.ximal end of the grain. A bubble 

 formation at the hilum sometimes accompanies this. As the starch in the immediate vicinity of 

 the reacting portion of the grain becomes affected, it is gelatinized and swells. The margin of the 



