434 



STARCHES OP CUPTJLIFER^. 



P I GV T P 



Chart No. 71. 



S T C I CA PA FC P S CI PA CA 

 " PC PS 



5 1 



Curve of Reaction-Intensities of Starch of Castanea 



sativa var. 



tint on the addition of iodine. The grains are lirighter and hghter in tint and the solution a purer 

 blue than in C. americana. When the grains are boiled for 2 minutes and then treated with iodine, 

 the solution becomes a deep indigo-blue and the grain-residues a blue-violet color, lighter in tint than 

 those of C. americana. When an excess of iodine is added most of the grain-residues become a deep 

 heliotrope in color, but some of the capsules take on a 

 wine-red of rather brighter tint than those of C. americana. 



Staining Reactions. With gentian violet and with 

 safranin the color of the grains after 30 minutes is verj' 

 light, about the same as that of C. americana. 



Temperature Reaction. The temperature of gelatini- 

 zation is 60 to 62 C, mean 61. 



Effects of Various Reagents. With chloral hydrate- 

 iodine the reaction begins immediately. The majority 

 of the grains are gelatinized in 30 seconds and all in a 

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

 americana, but the coloration of the grains which jire- 

 cedes the deep blue is not so reddish in tint, and the 

 color of the gelatinized grains is a purer blue than in the 

 grains of C. aynericana. 



Reaction with chromic acid begins immediately and 

 all Iiut very rare resistant grains are dissolved in 10 sec- 

 onds. In one of the latter the reaction took 30 seconds 

 for completion. The reaction is qualitatively the same as 

 in C. americana. 



The reaction with pyrogallic acid begins immediately. Most grains are gelatinized in 15 seconds 

 and all in 20 seconds. The reaction is qualitatively the same as in C. americana. 



With ferric chloride swelling begins in a few grains in 30 seconds. A small number are gelatin- 

 ized in a minute, the majority in 2 minutes, and all but very few resistant grains in 5 minutes. 

 The latter are generallj' gelatinized in 12 minutes, rarely not for 20 minutes. The reaction is quali- 

 tatively the same as in C. americana. 



The reaction with Purdy's solution begins at once. A few are gelatinized in 20 seconds, the 

 majority in 40 seconds, at least nine-tenths in a minute, and all but rare resistant grains in 2 minutes. 

 8uch resistant grains may not be gelatinized for 6 minutes, or rarely 10 minutes. The reaction is 

 qualitatively the same as in C. americana. 



STARCH OF CASTANEA PUMILA. (Plate 13, figs. 73 and 74. Chart 72.) 



Histological Characteristics. Infonn the grains are usually simple, and are isolated, except a 

 few which occur in clumps or in aggregates. There are a few compound grains, generally of two or 

 three components. A few isolated grains have clearly marked pressure facets. The irregularity of 

 the surface and the locations and structure of the protuberances are the same as in C. americana. 

 The conspicuous forms are ovoid, ellipsoidal, club-shaped with pointed distal end, somewhat bean- 

 shaped, and nearly round. There are some triangular with roundetl angles, lenticular, dome- 

 shaped, hemispherical, heart-shaped, and irregular grains of indefinite form. 



Either passing through or proceeding from the hilum, an elongated cleft is frequently found, with 

 or without radiating fissures. Occasionally the hilum may be observed as a clear, round, or lenticu- 

 lar spot, usually eccentric about one-third to one-fourth of the longitudinal axis. A single longitudinal 

 cleft frequently proceeds from the hilum, and sometimes a transverse cleft is found piercing it or 

 located slightly distal to it. These two fissures may occasionally intersect each other so as to form a 

 cross. The fissures are more frequently present and ai-e deej^er than those in the grains of C. americana. 



The lamrllw are rarely demonstraijle, and they are of similar structure to those noted under 

 C americana. On grains of fair size 7 may be counted. 



The grains vary in size from the smaller, which are 3 by 2ix, to the larger, which are 18 bj- 10,u 

 in length and breadth. The common siz(> is 10 by 7^ in length and breadth. 



Polariscopic Properties. The figures are the same as those noted for C. americana. The pro- 

 portion of grains in which the figure is of the bean type, consisting of an elongated line with 

 bisected ends, is rather higher than in C. americana. 



