424 STARCHES OF CUPULIFERiE. 



straight and at oblique angles, but more often at right angles than in Q. alba, and the lines are not 

 so often bent or bisected as in the Q. alba. 



The degree of polarization is fair to quite high. It often varies in the same aspect of a grain. 

 There is a smaller percentage of grains with quite high polarization than in Q. alba, and therefore, 

 on the whole, somewhat lower than in Q. alba. 



With selenite the quadrants are commonly well defined, slightly irregular in shape, and unequal 

 in size. They are usually regular in shape and equal in size in the smaller grains, and are therefore 

 more clearly defined than in the larger grains. The colors are about the same in brightness, vari- 

 ability, and purity as in Q. alba. 



Iodine Reactions. With 0.25 per cent Lugol's solution the grains color a blue-violet; with 

 0.125 per cent solution they slowly color a light blue-violet. After heating in water until all are 

 gelatinized and then adding iodine, the solution colors a deep blue and the gelatinized grains a bright 

 blue. When boiled for 2 minutes and then treated with iodine, the solution colors very deeply and 

 the grain-residues a bright blue. With an excess of iodine, the grain-residues color a deep blue 

 with a reddish tint, and most of the capsules a blue-violet, while a few are more of an old-rose tint. 

 The colors have slightly more of a reddish tint than in the grains of Q. alba so treated. 



Staining Reactions. With gentian violet some grains show a slight trace of violet immediately, 

 and in 30 minutes the color has deepened slightly. Some grains stain more than others. The vari- 

 ations and the depth of tint are about the same as in Q. alba. 



With safranin many grains stain a very light pink immediately, and in 30 minutes the color 

 deepens slightly. Some grains stain more than others. The color is deeper at the central cleft 

 and at the protuberances. The tint and the variations are about the same as in Q. alba. 



Temperature Reaction. The temperature of gelatinization is 62.5 to 64 C, mean 63.75. 



Effects of Various Reagents. With chloral hydrate-iodine the reaction begins in a few grains in 

 20 seconds. A few are gelatinized in 45 seconds, about five-sixths in 5 minutes, practically all in 7 

 minutes, and all in 15 minutes. The ungelatinized grains are of a deep golden-brown color, while 

 the gelatinized grains are of a fairly bright reddish-blue. This blue is not quite so reddish a tint 

 as in Q. alba. The reaction is qualitatively the same as in Q. alba. 



Reaction with chromic acid begins at once. It is complete in the majority of the grains in 40 

 seconds and in all in 60 seconds. The hilum or the region of the cleft at this region swells, and the 

 lamellae become very distinct. One line passes from the hilum in the ovoid forms, while small lines 

 pass out from the central cleft in the laterally extended grains. Gelatinization of the grain proceeds 

 rapidly. The capsule is finally ruptured, with extension of the contents of the capsule and solution 

 of both. The process appears to be qualitatively the same as in Q. alba, but it is much slower, so 

 that certain details can be observed. 



With pyrogallic acid reaction begins in about half at once and is complete in all the grains in 

 60 seconds. The process is qualitatively the same as in Q. alba. 



The reaction with ferric chloride begins in a few grains in 45 seconds. In 5 minutes a few have 

 begun to swell; in 10 minutes a very few are gelatinized; and in 15 minutes all the grains are in vari- 

 ous stages of gelatinization. The reaction is complete in one-fifth of the grains in 30 minutes, and 

 four-fifths are gelatinized and only a few scattered grains have resisted the reagent in 45 minutes. 

 No further change occurs in an hour. The reaction is qualitatively the same as in Q. alba. 



The reaction with Purdy's solution has begun in most grains in a minute. Only a very few 

 (perhaps 1 in 500) are gelatinized in 5 minutes, about 1 in 100 in 10 minutes, about one-tenth in 

 15 minutes, about nine-tenths in 30 minutes, and all but a few scattered grains in an hour. The 

 process is qualitatively the same as in Q. alba, but in most grains more lamellte remain ungelatinized 

 than those that are completely gelatinized. 



STARCH OF QUERCUS PRINUS. (Plate 11, figs. 65 and 66. Chart 66.) 



Histological Characteristics. Inform the grains are generally simple. A few doublets or compound 

 grains, usually of two components, are occasionally present. The simple grains are isolated, except a 

 few which occur in small aggregates and in clumps. The separate components of the aggregates have 

 clearly marked pressure facets. The conspicuous forms, as well as the non-conspicuous, are the same 

 as those noted for Q. alba, liut the ellipsoidal, ovoid, and lenticular grains are more numerous than 

 the somewhat bean-shaped grains. Grains with irregular surfaces due to the same cause as noted for 

 Q. alba are present, but the percentage of grains with regular surfaces is higher in this species. 



