868 



STARCHES OF RANUNCULACEiE. 



Staining Reactions. — With gentian violet the reaction begins immediately, but after 30 minutes 

 the color is not much deeper than at first. The grains are stained less than those of R. ficaria. 



With safranin the reaction begins very lightly in 30 seconds, but after 30 minutes the grains 

 are only sUghtly stained. They are not so deeply stained as those of R. ficaria. 



Temperature Reaction. — The temperature of gelatinization is 55" to 57° C, mean 56°. 



Effects of Various Reagents. — With chloral hydrate-iodine reaction begins in 30 seconds and is 

 over in 9 minutes. Both hilum and lamellffi are obscured. Some grains darken all over and then 

 swell; most of them show a beginning of reaction at the distal end, where a dark spot appears, 

 followed by much swelling, with protrusion, which process spreads over the grain. Sometimes there 

 is first bipolar swelUng, or swelling from irregular points on the margin. The gelatinized grains so 

 formed are fairly large and regular in outline. They show a dark marginal ring and often a dark 

 mass at the distal end and a lighter inner area. 



The reaction with chromic add begins as soon as the reagent touches the grains, which vanish 

 immediately. 



Reaction with pyrogallic add begins immediately and is over in a minute. The hilum swells 

 and the rest of the grain becomes divided by five or six deep radial cracks. As the whole grain 

 continues to swell these cracks open widely and the several parts of the grain become thinner and 

 clearer until finally a large gelatinized grain is formed, which is rather smooth at the proximal end 

 and folded and sacculated at the other. 



The reaction with ferric chloride begins immediately and is over in 30 seconds. The reaction 

 begins by the gelatinization of the distal end, then of the proximal end, and finally of the inner 

 central portion, which becomes divided by many fissures into small parts which fly apart and gelat- 

 inize independently. The gelatinized grains are large and very much crumpled and distorted. 



The reaction with Purdy's solution begins immediately and is over in 30 seconds. The distal 

 end swells, then the proximal end, and finally the central part. The gelatinized grains are large, 

 much distorted and sacculated at the distal end, and round and fairly smooth at the proximal end. 



The surface of the 



CI PA CA 

 POPS 



STAHCH OF RANUNCULUS FICARIA. (Plate 97, figs. 579 and 680. Chart 382.) 



Histological Characteristics. — In form the grains are usually simple. There are some compound 

 grains, no aggregates, a few clumps, and some grains with no pressure facets, 

 grains is quite smooth, but usually more or less irregu- 

 lar. The conspicuous forms are ovoid, round or nearly 

 round, oval, elliptical, pyriform, and triangular grains 

 with rounded angles. The grains are not flattened. In 

 a few grains there is the appearance of a hole or depres- 

 sion in the distal end, such as is seen in R. hulbosus. 



The hilum is fairly distinct. It is usually a small, 

 round, non-refractive spot, very eccentrically placed, 

 commonly about one-fifth of the longitudinal axis of the 

 grain, but always in the median line, and often showing 

 two radiating, non-refractive lines extending from it 

 towards the distal end. The hilum is often marked by a 

 slight fissure which extends transversely. It is frequently 

 double, and the two hila may be very close or far apart, 

 and may or may not be separated by a fissure. Usually 

 each hilum is immediately surrounded by its own lamellae, 

 which later fuse with those of the other hilum. 



The lamellm are usually not very distinct, but when 

 they can be made out they appear as comparatively 

 coarse, regular rings or segments of rings, one or two 

 of which are especially prominent. Those nearer the margin are more distinct than those near 

 the hilum, but they were not sufficiently defined to be accurately counted. 



The grains vary in size from 5 to 30;«; the common size is 18/t. 



Polariscojdc Properties. — The figure is eccentric and distinct. Its lines are sometimes clear- 

 cut and at other times more or less greatly diffused. If there are two hila the figures are somewhat 

 confused, but not bent or otherwise distorted. 



Curve of Reaction-Intenvities of Starch of Ranunculus 

 ficaria. 



