H.EMANTHUS. 



431 



per cent of the entire number of grains and 3 per cent of 

 the total starch in 5 minutes; 6 per cent of the entire 

 number of grains and 7 per cent of the total starch in 15 

 minutes; and in about 8 per cent of the grains and 10 

 per cent of the total starch in 30 minutes ; in about 10 

 per cent of the grains and 12 per cent of the total starch 

 in 45 minutes ; and in about 20 per cent of the grains and 

 30 per cent of the total starch in 60 minutes. (Chart 

 D87.) 



The reaction with nitric acid begins in a few grains 

 in 1 minute. Gelatinization occurs in about 1.5 per cent 

 of the total starch in 5 minutes ; in about 2 per cent of the 

 total starch in 15 minutes; in about 2.5 per cent of the 

 entire number of grains and 3 per cent of the total starch 

 iu 30 minutes; in about 3 per cent of the grains and 4 

 per cent of the total starch in 45 minutes ; and in about 

 the same percentage of grains and 6 per cent of the total 

 starch in 60 minutes. (Chart D 88.) 



The hilum swells and a small bubble which is often 

 quite transient appears at this point. The grains become 

 very refractive, the lamellae rarely becoming gradually 

 distinct previous to gelatinization. Numerous radiating 

 fissures may extend from the hilum, or there may be one 

 or more copiously branched longitudinal fissures, along 

 the course of which the mesial part of the grain becomes 

 disorganized into very brilliant, irregularly massed, re- 

 fractive granules, bounded by a refractive border which 

 soon breaks into linearly arranged granules at the distal 

 margin, and later at the proximal end if that becomes 

 gelatinized. All the granules toward the proximal end 

 are more resistant. Gelatinization may begin at the dis- 

 tal end when either that point or both ends of the grain 

 are narrowed. In such grains a longitudinal fissure is 

 sometimes traced from the hilum which becomes much 

 branched towards the distal end followed by gelatiniza- 

 tion of a small area accompanied by distention of the 

 capsule, which then assumes the appearance of a small 

 non-granular swelling that is sometimes bounded dis- 

 taHy by linear granules. 



The almost completely gelatinized grains are swollen, 

 but little distorted, and contain a few brilliant, linearly 

 placed granules. Very few grains, however, exhibit such 

 progress. They usually also contain mesial granules; 

 the capsule at the distal margin occasionally appears to 

 be dissolved and the refractive mesial granules more 

 scattered towards this end ; a refractive band at the proxi- 

 mal end and sides retains the outline of the untreated 

 grain. The few completely gelatinized grains are much 

 swollen and considerably distorted. 



The reaction with sulphuric acid begins in a few 

 grains in 1 minute. Complete gelatinization occurs in 

 about 5 per cent of the entire number of grains and 

 10 per cent of the total starch in 5 minutes; in about 20 

 per cent of the entire number of grains and 35 per cent 

 of the total starch in 15 minutes ; in about 40 per cent 

 of the grains and 79 per cent of the total starch in 30 

 minutes; in about 63 per cent of the grains and 90 per 

 cent of the total starch in 45 minutes; and in about 80 

 per cent of the grains and 94 per cent of the total starch 

 in 60 minutes. (Chart D 89.) 



The ungelatinized starch is found at the margin of 

 a few grains and about 1 per cent of all the grains are 

 unaffected to any appreciable degree. The grains become 



extremely refractive and the polariscopic properties are 

 quickly lowered without evidence of such in any micro- 

 scopical alteration in the grains. 



The reaction with hydrochloric acid begins in a few 

 grains in 1 minute. Complete gelatinization occurs in 

 about 1 per cent of the total starch in 5 minutes ; in about 

 3 per cent of the total starch in 15 minutes; in about 4 

 per cent of the entire number of grains and 10 per cent 

 of the total starch in 30 minutes; in about 12 per cent of 

 the total starch in 45 minutes ; and in about 5 per cent of 

 the grains and 15 per cent of the total starch in 60 min- 

 utes. (Chart D 90.) Experiment repeated with the same 

 results. 



The reaction with potassium hydroxide begins in rare 

 grains immediately. Complete gelatinization occurs in 

 about 0.5 per cent of the entire number of grains and 

 in about 1 per cent of the total starch in 5 minutes ; in 

 about the same in 15 minutes; in about the same per- 

 centage of grains and 2 per cent of the total starch in 

 30 minutes ; and in about the same as in the last obser- 

 vation in 60 minutes. (Chart D 91.) 



The reaction with potassium iodide begins in very 

 few grains in 1 minute. Complete gelatinization occurs 

 in about 1 per cent of the grains and 1.5 per cent of the 

 total starch in 5 minutes; in about the same percentage 

 of each in 15 minutes ; in about the same percentage of 

 each in 30 minutes; in about the same percentage of 

 grains and 2 per cent of the total starch in 45 minutes; 

 and in about 1.5 per cent of the grains and less than 3 

 per cent of the total' starch in 60 minutes. ( Chart D 92. ) 



The hilum swells slightly and any fissures thereat 

 become slightly enlarged, but no bubble was detected at 

 this region. The entire grain becomes very refractive 

 and the lamellaa are not usually demonstrable, though 

 occasionally one may be quite distinct and form a line of 

 demarcation between the main body of the grain and a 

 border which is little if any more refractive than the 

 main body of the grain. Fissures start from the hilum 

 which are delicate but varied in relation to the shape of 

 the grain; the fissures are often either unbranched or 

 slightly branched, though many branches may form in 

 the area where considerable gelatinization occurs, such as 

 at the distal end of elongated grains with eccentric 

 hilum. When the longitudinal fissure is unbranched, a 

 deep cluster of small fissures may extend inward from 

 the margin at one or more points previous to disorgan- 

 ization and gelatinization of this area. The course of 

 gelatinization is varied ; the most common form is for the 

 process to start along the median fissure and then to be 

 more rapid at one end, gelatinization becoming com- 

 plete at this point followed by swelling and distortion of 

 the capsule even when the remainder of the grain is but 

 little affected ; in elongated grains with a clearly defined 

 eccentric hilum the process may begin at the distal mar- 

 gin and advance gradually towards the proximal end ; in 

 another grain with a centric or nearly centric hilum the 

 process may advance from two ends towards the hilum. 

 The mesial region may be disorganized with the appear- 

 ance of a mass of refractive granules and disruption of 

 the marginal lamellae into linear granules ; but not infre- 

 quently the starch may first be broken into large refrac- 

 tive fragments. The most resistant starch is usually 

 located either at the proximal end and sides nearby, or 



