GENUS BRODI^A. 



593 



The hilum is distinct, and when not fissured it is a round spot, situated eccentrically about 

 one-third of the longitudinal axis of the grain, and usually in or near the median line. When it 

 is fissured, as is usually the case, the fissure may be small, straight, or with a double curve, and 

 clear-cut, transverse, or diagonal; or it may have tlu-ee arms, or be irregularly stellate with one 

 long arm extending in a longitudinal or diagonal direction. The hilum may be double, though 

 rarely, but more than two were not observed. 



The lamella are quite regular, fairly distinct, and coarse. They vary somewhat in different 

 grains and are larger near the margin than near the hilum. They tend to closely follow the outline 

 of the margin, but sometimes show irregularities. There are usually 6 to 10 lamelliE on a medium- 

 sized grain. 



The grains vary in size from 3 to 32;u. The common size is 16//. 



Polariscopic Properties. The figure is distinct and fairly clear-cut. Its lines may become 

 broader but less well defined at the margin and are often bent or otherwise distorted. Sometimes 

 the lines do not intersect at the hilum. 



The degree of polarization is fairly high. It is higher 

 in certain aspects of the grain than in others, and varies 

 in different grains. It is not so high as that of the grains 

 of B. peduncularis. 



With selenite the quadrants are fairly well defined, 

 irregular in shape, and unequal in size. The colors are 

 not quite pure. 



Iodine Reactions. With 0.25 per cent Lugol's solu- 

 tion the grains are colored deeply a blue-violet; with 0.125 

 per cent solution the grains tint lightly at first and then 

 the color deepens. The reaction is less than that of the 

 grains of B. peduncidaris. After heating until the grains 

 are all completely gelatinized, the solution colors very 

 faintly and the grains very deeply on the addition of 

 iodine. The grains are much swollen and somewhat sac- 

 culated and distorted. After boiling for 2 minutes the 

 solution is colored intensely, but the grain-residues less 

 deeply than before, and some not at all. When a very 

 slight excess of iodine is added the capsules color a red- 

 violet. Most of the capsules contain more or less blue-reacting starch in the proximal end. The 

 capsules are large and smooth at the proximal end, and sacculated, folded, and distorted at the 

 distal end. 



Staining Reactions. With gentian violet the grains stain very lightly at once and after 30 min- 

 utes are fairly well stained, more than those of B. peduncularis. 



With safranin the grains stain very lightly at once, but after 30 minutes are only lightly stained, 

 but more than the grains of B. pedunadaris. 



Temperature Reaction. The temperature of gelatinization is Gl to G3 C, mean 62. 



Effects of Various Reagents. With chloral hydrate-iodine some grains begin to react in a minute; 

 most of them show some reaction and many are completely gelatinized in 5 minutes. All except 

 one or two are completely gelatinized in 45 minutes. There is no further change. The process is 

 in all respects qualitatively the same as that in the grains of B. peduncularis. 



Reaction with chromic acid begins in many of the smaller grains immediately, is general in 30 

 seconds, and complete in 4 minutes. The process is identical with that in the grains of B. peduncularis. 



Reaction with pyrogallic acid is general in 30 seconds and is over in 3 minutes. The process 

 is identical with that of the grains of B. peduncularis. 



The reaction with ferric chloride begins in many grains in a minute and is general in 23^ 

 minutes. About five-sixths are completely gelatinized in 13 minutes, and the reaction is completed 

 in 30 minutes. The process is the same as that of the grains of B. peduncularis. 



With Purdy's solution the reaction begins at once in some smaller grains and is general in 30 

 seconds. None of the grains is fully gelatinized and very few are even partially gelatinized. The 

 process seems to consist merely in the slight swelling of the hilum, unless also in some cases the 

 innermost part of the grain may become gelatinous. 



Curve of Reaction-Intensities of Starch of Bi 

 Candida. 



MINUTES 

 dicea 



