GENUS RANUNCULUS. 869 



The degree of polarization is fairly high. It varies in different grains, in different aspects of 

 the same grain, and in different parts of tlie same aspect of a given grain. 



With selenitc the quadrants in most cases are not sharply defined, unequal in size, and irregular 

 in shape. The colors are not pure. 



Iodine Reactions. With 0.25 per cent Lugol's solution the grains color very deeply a blue- 

 violet, especially about the edge; with 0.125 per cent solution they are fairly deeply colored and more 

 deeply than the grains of R. bulbosus. After heating in water until all the grains are completely 

 gelatinized, the solution is slightly colored and the grains very deeply on the addition of iodine. 

 The grains are much swollen and distorted. After boiling for 2 minutes the solution is colored 

 more deeply, but the grain-residues much less. With excess of iodine the capsules take on a violet 

 coloration; all of them contain some blue-reacting starch. 



Staining Reactions. With gentian violet the reaction begins immediately and after 30 minutes 

 the grains are fairly deeply colored. The color is deeper than with R. bulbosus. 



With safranin the reaction begins immediately and the grains color quite deeply. After 30 

 minutes the stain has deepened somewhat. The grains are evenly stained, and the color is deeper 

 than in the grains of R. bulbosus. 



Temperature Reaction. The temperature of gelatinization is 63 to 65 C, mean 64. 



Effects of Various Reagents. With chloral hydrate-iodine reaction begins in some grains in 30 

 seconds and the reaction is practically over in 30 minutes. Both hilum and lamellae are obscured. 

 A clear, dark area is formed about the margin which spreads inward. This area continues to darken, 

 especially at the distal end of the grain, and sometimes at both ends. There is usually much swell- 

 ing at two points at the distal end. Following this, the hilum and one or two nearby points swell in 

 the form of little knob-like projections. This process extends around the margin and in the larger 

 grains it is apt to proceed along one side more rapidly than the other. Thus, the imaffected central 

 part of the grain becomes surrounded by an irregular, saccular gelatinous ring. The process finally 

 extends all over the grain. The gelatinized grains are large and distorted. The margin is dark and 

 very irregular, and within this is a lighter space somewhat irregularly crossed by dark lines and 

 surrounding a dark mass at the center that is divided by light fissures. 



The reaction with chromic add begins immediately and is over in about 20 seconds. It is so 

 rapid that it is difiicult to distinguish the individual steps. The process seems to consist of rapid 

 swelling, first of the hilum, which swells out at the end of the grain, and then of the whole grain, 

 the inner part swiftly passing into a gelatinous mass. The distal end of the grain is dissolved at one 

 point and the capsule opens, and the granular mass within flows out and dissolves, followed by solu- 

 tion of the capsule. 



Reaction with pyrogallic add begins in 20 seconds and is over in 3 minutes. The hilum swells 

 greatly, expanding the proximal end of the grain. The other parts become divided by five or six 

 deep radial fissures which extend almost to the margin. These open more and more widely, and 

 more such fissures appear as the hilum, or rather the whole grain, swells, so that finally the swollen 

 grain has the appearance of a number of small pyramids at the base and a large, clear space above 

 bordered by a thick, homogeneous band. The pyramids soon become clear and finally gelatinize, 

 followed by gelatinization of the marginal band, forming a large gelatinized grain which is smooth 

 at the proximal end and folded and sacculated at the other. 



With ferric chloride the reaction begins in 20 seconds and is over in 3 minutes. The hilum and 

 lamellae are not very distinct. The lower part of the margin first reacts with great swelling and 

 irregular protrusion. Then the hilum swells out in the form of a small knob. These two parts 

 become connected by the spreading reaction on both sides, so that there is formed an irregular, 

 gelatinous ring which incloses the unaffected central part of the grain. This central portion becomes 

 divided by fissures into small pieces which gelatinize separately. The process, however, does not take 

 place so rapidly as in the grains of R. bulbosus. The gelatinized grains are very large, much 

 crvunpled, and distorted. The distal end has folds arranged according to lines of the lamellae and the 

 proximal end is swollen and wrinkled. 



The reaction with Purdy's solution begins immediately and is over in about 25 seconds; the 

 steps could not satisfactorily be distinguished. It appears that the hilimi swells greatly and that 

 the other parts of the grain are soon gelatinized, forming a large mass, which is smooth and saccular 

 at the proximal end, but folded in lamellar form at the other. 



