GENUS CASTANEA. 433 



deepens rapidly. The tint in each case is about the same as in C. americana. After heating in water 

 until all the grains are gelatinized and then treating with iodine, the solution colors a deep helio- 

 trope and the grains a fairly deep blue with a reddish tint, slightly more of the red than in C. ameri- 

 cana. When the grains are boiled for 2 minutes and then treated with iodine, the solution becomes 

 a deep bluish-purple and the grain-residues a very light blue, some with reddish tint. When an 

 excess of iodine is added, the grain-residues and the solution deepen in tint and the capsules color 

 a deep heliotrope to a wine-red, more reddish than in C. americana. 



Staining Reactions. With gentian violet the grains show a very faint trace of violet at once 

 and in 30 minutes the}' are very lightly stained. The coloration is about the same as in C. americana. 



With safranin the grains do not stain immediately, and in 30 minutes there is simply a trace 

 of the stain. The coloration is about the same as C. americana. 



Temperature Reaction. The temperatiu'e of gelatinization is 59 to 61 C, mean 60. 



Effects of Vaiiovs Reagents. With chloral hydrate-iodine reaction begins immediately. Several 

 grains are gelatinized in 10 seconds, the majority in 30 seconds, all but a few resistant grains in 45 

 seconds, and all in a minute. The reaction is qualitatively the same as in C. americana. 



The reaction with chromic acid begins at once and practically all the grains are dissolved in 5 

 seconds, and all in 10 seconds. The reaction is qualitatively the same as in C. a7nericana. 



Reaction with pyrogallic acid begins immediately. The reaction is complete in practically all the 

 grains in 10 seconds, and in all in 15 seconds. The reaction is qualitatively the same as in C. americana. 



With ferric chloride reaction begins in a few grains in 30 seconds. About half are gelatinized 

 in a minute, two-thirds in 2 minutes, nearly all in 3 minutes, and all but rare resistant grains in 5 

 minutes. The latter may take from 8 to 10, rarely 15, minutes for the completion of the reaction. 

 The reaction is qualitatively the same as in C. americana. 



The reaction with Purdy's solution begins immediately. A few grains are gelatinized in 20 

 seconds, the majority in 30 seconds, four-fifths in a minute, and all but rare resistant grains in 5 

 minutes. The reaction is usually complete in the latter in 8 minutes, but rarely takes 30 minutes. 

 The grains in which reaction is slow are those of rather small size with a regular outline. The reac- 

 tion is qualitatively the same as in C. americana. 



STARCH OF CASTANEA SATIVA VAR. (Chart 71.) 



The preparation was made from a large "Italian chestnut," which was not identified. 



Histological Characteristics. Inform the grains are usually simple, and are isolated, except some 

 which occur in clumps and a small number in aggregates. There are a few compound grains of few 

 components. Some isolated grains have well-marked pressure facets. The irregularity of the sur- 

 face and the locations and structure of the protuberances are identical with those of C. americana. 

 The conspicuous forms are the same as those noted under C. americana, but a greater proportion of 

 grains are large or have irregular outlines. 



The hilum is not usually demonstrable. Occasionally an irregular cavity or elongated cleft may 

 be distinguished at its position, and very rarely it is observed as a round spot, usually two-fifths 

 to one-fifth eccentric of the longitudinal axis; it may be centric. A single longitudinal cleft with or 

 without radiating fissures may proceed from the hilum. Sometimes the hilum may be pierced by 

 a short transverse or diagonal cleft, or these fissures may be located slightly distal to the hilum. 



The lamellae are not usually demonstrable, but when observed are of similar structure to those 

 noted under C americana. Occasionally 6 to 8 lamellse may be counted on the large grains. 



The grains vary in size from the smaller, which are 4 by 3;ti, to the larger, which are 22 by 12ju 

 in length and breadth. The common size is 12 by 7/u in length and breadth. 



Polariscopic Properties. The figure is in all essential respects identical with that observed 

 in C. americana. 



The degree of polarization is fair to high. The proportion of grains in which it is high is greater 

 than in C. americana. 



With selenite the definition, size, and shape of the quadrants is identical with that noted for 

 C. americana. The purity of the colors is the same as in C. americana. 



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

 which becomes very deep in 2 minutes; with 0.125 per cent solution the grains color a fairly deep 

 blue-violet, which becomes quite deep in 2 miimtes. After heating the grains in water until all 

 are gelatinized, the solution becomes a deep blue and the grains a bright blue with a slightly reddish 



