GENUS ZINGIBER. 



785 



With safranin the grains begin to stain in a minute. After 30 minute.s they are lightly stained, 

 sliglitly less than in Z. officinale. 



Temperature lieadiun. The temperature of gelatinization is 89.5 to 90.5 C, mean 90. 



Effects of Various Reagents. With chloral hydrate-iodine the reaction begins in some of the 

 injured grains in 30 seconds and these are completely darkened, though not fully swollen, in 3 min- 

 utes. The reaction begins in the intact grains in 2J^ minutes and is complete in all in 10 minutes. 

 The hilum is prominent as a dark spot. The grain becomes clearer and darker around the margin, 

 the lower portion darkens and swells somewhat and the process extends upward over the other 

 parts of the grain. It usually spreads more rapidly up the margin than over the central portion. 

 Sometimes the distal end becomes dark and the hilum swells at the same time. The reaction then 

 extends over the grain from these two points. After the grains are darkened, they swell, and irreg- 

 ular fissures appear. There is usually a very light space of varying shape at the proximal end, 

 representing the swollen hilum. After 2 or 3 hours the grain often shows a transverse fissure which 

 nearly separates the grain into 2 parts. 



Reaction with chromic acid begins in 2 minutes and is complete in 11 minutes. The hilum is 

 very distinct and also some of the lamellis. Two non-refractive lines extend outward and down- 

 ward on either side of the hilum, thus outlining an inner, fan-shaped area, which becomes divided 

 into granules by many fine fissures which are very wide at the proximal end. The whole mass be- 

 comes gelatinized. The marginal starch above the hilum is more resistant and appears as a broad, 

 quite homogeneous band. The gelatinized grain so formed is now dissolved at one point, usually 

 the distal end. The gelatinous starch inside flows out and is dissolved. The more resistant, marginal 

 starch in the region of the hilum dissolves more slowly and finally the entire grain has disappeared. 



The reaction with pyrogallic acid begins in about 5 minutes in those grains which are not under- 

 neath the cover-slip, and all of these are completely gelatinized in 20 to 25 minutes. Those under- 

 neath the cover-slip do not react. The hilum is prominent, and the lamellae may be made out in 

 some grains. The imier part of the grain may either be changed into a gelatinous mass or it may be 

 divided by a perpendicular irregular fissm-e and the grain be broken up into granules which become a 

 gelatinous mass, the result being the same as that of the first method. The gelatinized gi-ains so 

 formed are thin-walled, large, somewhat irregular, but rounded in outline and without much wrink- 

 ling and folding. 



With feiTic chloride the reaction begins in a few in 3 minutes and is complete in all in 55 minutes. 

 The hilum is prominent, but the lamellae can not be seen. The whole interior of the grain is changed 

 into a gelatinous, gi-anular mass and swells out, forming a large, irregular, thin-walled mass, which 

 is at first smooth and rounded; later the capsule becomes wrinkled and folded. In some grains a 

 number of irregular fissures may extend from the hilum to the distal end, along the longitudinal 

 axis, and subsequent to this the imier portion of the grain becomes a gelatinous mass, with swelling, 

 and the final formation of a large gelatinized grain. 



There is no reaction to Purdy's solution after 2 hours. 



Differentiation of Certain Starches of the Genus Zingiber, 



Histological Characteristics. 

 Conspicuous Forms. 



Z. officinale: Usually simple, rarely compound, no aggre- 

 gates, no pressure facets, surface somewhat irregular 

 owing to small rounded protuberances and nipple- 

 like projections, the latter especially at proximal end, 

 flattened, flattened ovoid, curved longitudinally, 

 especially the proximal end, proximal end usually 

 pointed. 



Z. officinale var. Jamaica No. 1: Essentially the same 

 as in Z. officinale, except that the conspicuous 

 grains are short, broad ovoid and oval. 



Z. officinale var. Jamaica A'o. 3: Essentially the same 

 as in Z. officinale var. Jamaica No. 1 . 



Z. officinale var. Cochin: Essentially the same as Z. 

 officinale var. Jamaica No. I. 



Hilum Form, Number, and Position. 

 Z. officinale: Form not usually visible, small round spot, 

 never fissured. No double hila. Position extremely 

 eccentric. 



Histological Characteristics. Continued. 

 Hilum Form, Number, and Position. Continued. 



Z. officinale var. Jamaica No. 1: Form not distinct, 

 small round spot, occasionally shghtly fissured, no 

 double hila. Position very eccentric. 



Z. officinale var. Jamaica No. 2: Form fairly distinct, 

 medium-sized round spot, not fissured, no double 

 hila. Position very eccentric. 



Z. officinale var. Cochin: Form rarely visible, small 

 round spot, not fissured, occasionally double hila. 

 Position very eccentric. 



Lamella: General Characteristics and Number. 



Z. officinale: Very distinct, fine, regular. About 57. 



Z. officinale var. Jamaica No. 1: Fairly distinct, fine, 



regular. Not determined. 

 Z. officinale var. Jamaica No. 2: Usually not visible; 



fine, regular. Number not determined. 

 Z. officinale var. Cochin: Very indistinct, fine, regular. 



Number not determined. 



