PHAIUS. 



739 



throughout the entire grain, is telescoped; a group of 

 refractive granules remain moderately often at the proxi- 

 mal end which is sometimes either concave or raised into 

 a rounded eminence, with depressions on either side. 

 The gelatinized grains do not resemble the form of the 

 untreated grain. 



The reaction with pofiassium sulphocyanate begins 

 immediately. Complete gelatinization occurs in about 81 

 per cent of the entire number of grains and 97 per cent 

 of the total starch in 5 minutes; in about 93 per cent of 

 the grains and 98 per cent of the total starch in 10 

 minutes; in about 95 per cent of the grains and 99 per 

 cent of the total starch in 15 minutes. (Chart D 582.) 



The hilum swells and the lamelke become sharply 

 defined. Gelatinization more frequently advances quite 

 rapidly through the mesial portion to the distal margin 

 without the formation of definite fissures, a marginal 

 border at the proximal end and sides being the most 

 resistant. In a few grains gelatinization may begin at 

 the proximal end, accompanied by the distention of the 

 capsule, giving rise to the appearance of a small, clear 

 swelling; later it proceeds as described above, the most 

 resistant part being the lateral marginal border, and 

 occasionally also the distal border. The mesial portion is 

 broken down into moderately refractive granules, a group 

 of which are larger, quite refractive, and located around 

 the area of the hilum. This marginal border is very re- 

 fractive, but gradually the lamella; of which it is com- 

 posed become sharply defined and striated, and often 

 break down into linear, very refractive granules previous 

 to gelatinization. The gelatinized grains are much swol- 

 len and distorted, more at the distal than proximal end. 

 They do not resemble the untreated grain. 



The reaction with potassium sulphide begins imme- 

 diately. Complete gelatinization occurs in about 89 per 

 cent of the entire number of grains and over 99 per cent 

 of the total starch in 2 minutes; in about 98 per cent of 

 the grains and over 99 per cent of the total starch in 

 5 minutes. ( Chart D 583.) 



The reaction is so rapid that the minute steps can not 

 be determined. The gelatinized grains are much swollen 

 and distorted, usually telescoped at the distal region, and 

 a considerable number are telescoped throughout the 

 entire grain, with a concave invagination at the proxi- 

 mal end. When the grains are not distorted at the proxi- 

 mal end, the wall is moderately thick and the remains 

 of 2 or 3 lamella; can be traced in addition to the capsule. 

 The gelatinized grains do not resemble the form of the 

 untreated grain. 



The reaction with sodium hydroxide begins imme- 

 diately. Complete gelatinization occurs in 48 per cent 

 of the entire number of grains and 78 per cent of the 

 total starch in 2 minutes; in about 73 per cent of the 

 grains and 95 per cent of the total starch in 5 minutes; 

 in about 98 per cent of the grains and 99 per cent of the 

 total starch in 15 minutes. (Chart D 584.) 



A small bubble is occasionally detected at the hilum, 

 which frequently remains small and is very transient, 

 though in a few grains it expands considerably, and its 

 expulsion is followed by an invagination at the proximal 

 end. The lamella; become very sharply defined and 

 striated, with the exception of a narrow, refractive border 

 at the proximal end and sides. Gelatinization often pro- 

 ceeds without the formation of clearly defined fissures, 

 though 2 oblique fissures may pass from the hilum to- 



ward the distal end, while fissures are generally clear-cut, 

 but occasionally branched towards the distal end. The 

 mesial portion of the grain is generally disorganized 

 without the appearance of refractive granules, with the 

 exception of a group of quite large, very refractive gran- 

 ules which often appear in the area near and around the 

 hilum. A few lamellae at the distal margin are quite 

 resistant, but generally gelatinize without the appear- 

 ance of granules. A narrow, refractive border at the 

 proximal end and sides, rarely surrounding the entire 

 grains, is the most) resistant part of some grains, but it 

 becomes gelatinized without previously breaking down 

 into granules. The grains which are most quickly gela- 

 tinized are first attacked at the proximal end, followed 

 quickly by a gelatinization of the refractive border along 

 the sides, an area in the middle of the distal border 

 proving the most resistant. 



The gelatinized grains are much swollen and dis- 

 torted, with a tendency to telescopic folds and to lateral 

 extension at the distal margin ; a moderate proportion is 

 thrown into telescopic folds throughout the grain, with 

 either a depression or a concave invagination at the proxi- 

 mal end. The grains are completely gelatinized, no group 

 of granules remaining at the proximal end, as found 

 with some reagents. The gelatinized grains do not re- 

 semble the untreated grain. 



The reaction with sodium sulphide begins imme- 

 diately. Complete gelatinization occurs in about 50 

 per cent of the entire number of grains and 84 per cent 

 of the total starch in 2 minutes ; in about 73 per cent of 

 the grains and 95 per cent of the total starch in 5 min- 

 utes ; in about 95 per cent of the grains and 99 per cent 

 of the total starch in 15 minutes. (Chart D585.) 



A bubble appears at the hilum, which expands to con- 

 siderable size. The lamellae immediately become sharply 

 defined and striated, with the exception of a narrow re- 

 fractive border at the proximal end and sides ; the lamellae 

 in the latter, however, may gradually become defined 

 previous to gelatinization. No well-defined fissures are 

 formed. The starch in both the mesial 'and marginal re- 

 gions is disorganized without the appearance of refractive 

 granules. The process more frequently begins at the 

 proximal margin and may extend along the lateral re- 

 fractive border accompanied by a ruffling or fluted appear- 

 ance of this border; the reaction may then appear at the 

 distal corners and margin before much progress has been 

 made in the mesial region. In the more resistant grains, 

 the bubble at the hilum is more persistent; upon its 

 expulsion the lamella? through the mesial region become 

 undulating, followed by gelatinization as far as to a few 

 lamella? at the distal margin, accompanied by lateral dis- 

 tention here, and often gelatinization with distortion 

 at the distal corners and in a narrow border along the 

 margin before a few lamellae just within the distal mar- 

 gin are gelatinized. In such grains the narrow, refractive 

 border at the proximal end and sides is the most resistant ; 

 the lamella? composing this border may become sharply 

 defined and striated, but are disorganized without the 

 formation of granules. 



The gelatinized grains are much swollen and dis- 

 torted, frequently with telescopic folds throughout the 

 lateral margin, and with either a flattening with a cen- 

 tral prominence or a concave area at the proximal end; 

 many grains, however, have a few telescopic folds near 

 the distal margin, with convolutions at the corners, the 



