GENUS BRODI^A. 



599 



of the margin. Nipple-like processes are not common. The conspicuous forms are ovoid, oval, and 

 ellipsoidal. The broader forms are not so thick as broad; and the distal end is apt to be narrower 

 than the proximal, so that on edge the grains appear of an elongated, ovoid form. 



The hilum is distinct and nearly always marked with fissures. It is eccentric about one-third 

 of the longitudinal axis of the grain. There are probably compound grains with 2 or more hila 

 which are likely obscured by fissures. The fissures are usually very deep and wide, less commonly 

 they are small, single, transverse or diagonal lines, but usually the fissuration is in the form of a 

 more or less clear-cut cross. There may be one fissure at the hilum and another rather irregiilar 

 fissure between the hilum and the distal end. There are also at times irregularly stellate and 3- 

 armed fissures. Fissuration is less marked than in B. "peduncular is. 



The lamellce are fairly distinct, rather coarse, regular, continuous lines which follow the out- 

 line of the margin. Those near the hilum are more distinct than those at the distal end. They are 

 arranged apparently so that a group of rather fine, indistinct lamellae alternate with a single, coarse, 

 and distinct lamella. The hilum is usually situated in a small, non-lamellated space. There are 

 probably on the larger grains about 12 lamellae, but the 

 number could not be determined with accuracy. 



The grains vary in size from 5 to 5"ix. The common 

 size is 32m. The common dimensions of a large, ovoid 

 grain are 38 by 32/i in length and width. 



Polariscopic Properties. The figure is eccentric and 

 distinct, not clear-cut. Two of the lines are often blurred 

 and indistinct as they near the margin and slightly bent 

 or otherwise distorted. 



The degree of polarization is fairly high, except near 

 the distal end and margin of some of the grains. It is 

 somewhat less than that of the grains of B. peduncularis. 



With selenite the quadrants are not well defined, are 

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

 colors are not piu-e. 



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

 tion the grains color at once a deeply blue violet; with 

 0.125 per cent solution they color lightly at first, but the 

 color soon deepens. Some grains are much more deeply 

 colored than others. The shade is about the same as that 

 of B. pedunadaris. After heating until the grains are completely gelatinized, the solution colors 

 fairly and the grains deeply with iodine. After boiling for 2 minutes the solution colors very deeply, 

 the grain-residues very hghtly or not at all. The capsules color a dark red-violet when a slight 

 excess of iodine is added and many still contain some blue-reacting starch at the proximal end. 



Staining Reactions. With gentian violet the grains begin to stain at once and in 30 minutes 

 are fairly deeply stained, some more deeply than others. All are colored more than the grains of 

 B. peduncularis. 



With safranin the grains begin to stain at once and in 30 minutes are lightly stained, some more 

 than others. The color is the same as that of the grains of B. peduncularis. 



Temperature Reaction. The temperature of gelatinization is 67 to 68 C, mean 67.5. 



Effects of Various Reagents. With chloral hydrate-iodine a few grains show a reaction in 30 

 seconds. A few are darkened in 5 minutes and about one-third show some signs of reacting without 

 much change in 10 minutes. A few more are darkened and there is a slight advance in the reaction 

 in the other grains in 15 minutes. About one-fourth are darkened and some of the rest are affected 

 in 30 minutes. About one-third are dark and a few more partially darkened and gelatinized in an 

 hour. The reaction is qualitatively the same as that of the grains of B. peduncularis. 



Reaction with chromic acid begins in a few grains in 30 seconds. About one-fourth are affected 

 in IH minutes and two-thirds in 2i/^ minutes. At this time some of the grains have undergone com- 

 plete solution. All the grains react within 33^ minutes and the reaction is over in 9 minutes. The 

 process is quahtatively the same as that of the grains of B. peduncularis. 



With pyrogallic acid a few react in 30 seconds and a few more in 1 J/^ minutes. About one-fourth 

 to one-third are almost completely gelatinized in 6 minutes, and the remainder are in all stages of 

 40 



Curve of Reaction-Intensities of Starch of Brodisa 

 californica. 



