674 



STARCHES OF AMARYLLIDACEiE. 



Polariscopic Properties. — The figure is usually not clear-cut, but commonly distinct. One or 

 two lines may be very broad and indistinct, and they are often much bent or otherwise distorted, 

 often especially at the margin of the grain. 



The degree of polarization is high. It is very variable in different grains, and varies in differ- 

 ent aspects of the same grain. It may be absent in some parts and very low in certain other parts 

 of the same grain. It is lower than in the grains of N. horsfi^ldii. 



With selenite the quadrants are not as a rule sharply defined and are very irregular in shape 

 and unequal in size. The colors are sometimes pure. 



Iodine Reactions. — With 0.25 per cent Lugol's solution the grains are colored deeply a blue- 

 vnolet; with 0.125 per cent solution they tint lightly and the color deepens slowly. The color is 

 slightly deeper than that in the grains of N. horsfieldii. 

 After heating in water until the grains are completely gel- 

 atinized, the solution is colored deeply and the grains 

 very deeply on the addition of iodine. After boiling for 

 2 minutes the solution is colored much deeper, but the 

 grain-residues much less deeply. All the capsules contain 

 some blue-reacting starch. With an excess of iodine the 

 capsules are colored blue. 



Staining Reactions. — With gentian violet the grains 

 stain at once lightly and after 30 minutes are fairly 

 stained. The color is slightly less than that of the grains 

 of N. horsfieldii. 



With safranin the grains begin to stain very lightly 

 in 30 seconds, and in 30 minutes are slightly stained. 

 The color is less than that of the grains of N. horsfieldii. 



Temperature Reaction. — The temperature of gelatin- 

 ization is 72.5° to 74° C, mean 73.25°. 



Effects of Various Reagents. — With chloral hydrate- 

 iodine there is a reaction in many grains in 4 minutes. 

 About three-fourths of the grains are gelatinized in an 

 hour. The remaining one-fourth are, as a rule, unaffected. There was no further change. The 

 reaction is quaUtatively the same as that in the grains of N. horsfieldii. 



With chromic add there is a general reaction in a minute which is over in 9 minutes. It is qual- 

 itatively the same as that of the grains of N. horsfisMii. 



There is a general reaction with pyrogallic acid in 2 minutes and in 35 minutes about half 

 are fully gelatinized. The other half of the grains are affected and in all stages of reaction. 

 There was no further change. The reaction is qualitatively the same as that of the grains of N. 

 horsfieldii. 



With ferric chloride a number of grains begin to react in 3 minutes and all are not affected, but 

 alx)ut one-fifth are fully gelatinized in 10 minutes. All are reacting and almost all completely gelat- 

 inized in 45 minutes, and the reaction is complete in IJ^ hours. The reaction is quahtatively the 

 same as that of the grains of N. horsfieldii. 



Reaction with Purdy's solution begins in a few grains in 2 minutes, but at the end of an hour 

 only a few more were affected and only one or two were completely gelatinized. There was no fur- 

 ther change. The reaction is qualitatively the same as that of the grains of N. horsfieldii. 



STARCH OF NARCISSUS BIFLORUS. (Plate 61, figs. 361 and 362. Chart 236.) 

 Histological Characteristics. — In form the grains are usually simple. There are very few com- 

 pound grains and aggregates. Pressure facets are very rare. The surface of the grains is generally 

 irregular, owing to additions in the form of rounded protrusions and nipple-like projections. The 

 conspicuous forms are the ovoid to the oval and elliptical. There are some spherical, irregular 

 quadrangular forms with rounded angles, lenticular, triangular, and various irregular forms. The 

 triangular and quadrangular forms are about three-fourths as thick as they are broad, and the ovoid 

 and other forms generally are as thick as they are broad. 



The hilum, when not fissured, is an indistinct, small, round or rarely lenticular spot, usually 

 eccentric about one-third to two-fifths of the longitudinal axis, and either in or slightly to one side 



Curve of Reaction-Intensities of Starch of 

 Narcissus poeticus. 



