GENUS NARCISSUS. 



677 



STARCH OF NARCISSUS JONQUILLA VAR. RUGULOSUS. (Plate 61, figs. 365 and 366. Chart 238.) 



Histological Characteristics. — In form the grains are simple. A few occur in aggregates. Poorly 

 defined pressure facets are rarely seen. The surface is generally irregular, owing to inequalities of 

 development. In some cases the grains often have an outer coating of starch, which is not lamellated, 

 except when the primary grain is very small. The conspicuous forms are the ovoid to oval and 

 elliptical; also lenticular, irregularly quadrilateral and triangular with rounded comers, reniform, 

 and almost spherical. The quadrilateral and reniform and some of the broad ovoid forms are from 

 one-half to three-fourths as thick as they are broad. 



The hilum is a small, not very distinct, round or lenticular spot, usually eccentric about one- 

 third of the longitudinal axis of the grain and in or to one side of the median line. It is generally 

 fissured, and the fissuration is usually in the form of a single, small, and clean-cut, straight, trans- 

 verse line. It may be as a cross or a variable arrangement, especially in an irregularly stellate 

 fashion. No multiple hila were observed. 



The lamella are usually indistinct, but when they can be seen they appear as rather coarse, 

 continuous, regular rings which follow the outline of the margin. There are about 6 to 10 on the 

 larger grains. 



The grains vary in size from 4 to 50/u. The common size is 28/1. 



Polariscopic Properties. — The figure is usually eccentric, distinct, and often clear-cut, but one 

 or more of its lines may become broader and less well defined in some part of their course. The 

 lines are also sometimes bent and otherwise distorted. 



The degree of polarization is high. It varies some- 

 what in different grains, in different aspects of the same 

 grain, and often very greatly in different parts of the 

 same aspect of a grain. It is slightly higher than that of 

 the grains of N. horsfiMdii. 



With selenite the quadrants are usually well defined, 

 generally irregular in shape, and unequal in size. The 

 colors are usually pure. 



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. The color is slightly 

 deeper than that of the grains of N. horsfieldii. After 

 heating in water until the grains are completely gelatin- 

 ized, the solution colors fairly and the grains very deeply 

 on the addition of iodine. After boiling for 2 minutes, 

 the solution colors very deeply and the grain-residues 

 not very deeply. The capsules all color a red-violet 

 with an excess of iodine and most of them retain blue- 

 reacting starch. 



Staining Reactions. — ^With gentian violet the grains begin to stain very slightly in a minute and 

 in 30 minutes are fairly stained. The color is not quite so deep as that of the grains of N. liorsfiMii. 



With safranin the grains begin to stain very lightly at once and in 30 minutes are fairly stained. 

 The color is not quite so deep as that of the grains of A'', horsfieldii. 



Temperature Reaction. — The temperature of gelatinization is 74.5° to 76° C, mean 75.25°. 



Effects of Various Reagents. — With chloral hydrate-iodine reaction begins in 2J^ minutes. About 

 one-fourth of the grains are gelatinized in 10 minutes, one-half in 15 minutes, three-fourths in 23 

 minutes, and five-sixths in 15 minutes. The reaction is qualitatively the same as that of the grains of 

 A'^. horsfieldii. 



The reaction with chromic acid begins in 45 seconds and is over in 4 minutes. It is qualitatively 

 the same as that of the grains of A'^. horsfieldii. 



Reaction with pyrogallic acid begins in 45 seconds and is over in 15 minutes. It is qualitatively 

 the same as that of the grains of A^. horsfieldii. 



The reaction with ferric chloride begins in a few grains in 13^ minutes. About three-fourths 

 are gelatinized in 10 minutes and all in 40 minutes. The reaction is qualitatively the same as that 

 of the grains of A^. horsfieldii. 



Curve of Reaction-Intensities oi Starch of Narcisstu 

 jonquilla vfir. mgulosus. 



