NARCISSUS. 



517 



The hilum is distinct and a bubble is never formed 

 there. The lamella; are moderately distinct in some 

 grains and indistinct or invisible in others. Gelatiniza- 

 tion begins at the hilum. First the starch immediately 

 around the hilum is divided into particles or large gran- 

 ules, and longitudinal fissures extend irregularly from 

 the hilum to the distal margin, dividing the material in 

 their path into granules of varying size. The material 

 not included in this fissuring becomes coarsely striated. 

 The grains now begin to swell and the less resistant 

 portion is gelatinized, especially the granular matter 

 between the hilum and the distal margin. The more 

 resistant starch is pushed to the margin, where it forms 

 a baud which extends all the way or only part of the way 

 around the margin and consists of two parts an outer, 

 refractive, coarsely striated, lamellated ring, and an 

 inner, less refractive, spicular ring with a fringed inner 

 border that incloses coarse granules. As fast as these 

 granules arc gelatinized, others are formed from the 

 fringed inner band, which arc gelatinized. Finally, 

 only the outer, striated, lamellated band is left, and in 

 the grains in which gelatinization is complete before dis- 

 solution occurs, the stria become at first coarser and 

 more distinct, while the lamellated appearance disap- 

 pears, then the striaa become indistinct, and finally only 

 a nearly transparent and homogeneous-looking capsule is 

 left. In a few grains in which there is a very clear dis- 

 tinction between primary and secondary starch deposits, 

 the former is broken into 3 or 4 large particles which are 

 scattered around the inner border of the marginal baud, 

 which in these grains consists of only one portion which is 

 coarsely striated and lamellated. The particles of the 

 primary starch in such grains are very resistant and 

 the last part of the grain to be gelatinized. 



The gelatinized grains are much swollen, have rather 

 thick capsules, and are not much distorted. Usually, 

 however, the capsule is dissolved in one place before the 

 rest of the grain is completely gelatinized and the contents 

 of the capsule are gelatinized and flow out and are dis- 

 solved, leaving only the thin capsule which first separates 

 into several pieces and then is dissolved. 



The reaction with pyroyaUic acid begins in a few 

 grains in 1 minute. Complete gelatinization occurs in 

 about 1 per cent of the entire number of grains and 2 

 per cent of the total starch in 5 minutes ; in about 3 per 

 cent of the grains and 20 per cent of the total starch 

 in 15 minutes ; in about 22 per cent of the grains and 68 

 per cent of the total starch in 30 minutes ; in about 38 

 per cent of the grains and 81 per cent of the total starch 

 in 45 minutes ; in about 48 per cent of the grains and 88 

 per cent of the total starch in 60 minutes. (Charts 

 D261 and D262.) 



The hilum is distinct and a bubble is never formed 

 there. The lamella? are moderately distinct in some 

 grains, very distinct in some, and not distinct in the 

 others. Gelatinization begins at the hilum and progresses 

 according to two methods. In the great majority of the 

 grains the starch immediately surrounding the hilum 

 is split into a great number of rather coarse granules, 

 and the rest of the material of the grain is divided by 

 very fine striae. The less resistant portion of the grain 

 is gelatinized and the grain swells, slowly pushing the 

 more resistant starch to the margin where it forms 



a finely striated, lamellated band, around the inner bor- 

 der of which are arranged the granules IWmnl from the 

 material immediately surrounding the hilum, which in 

 some cases at least certainly represents a primary starch 

 formation. These granules are very resistant; they 

 slowly grow smaller and more refractive and often re- 

 main for some time after the rest of the grain is gelati- 

 nized. In the marginal band the lamellated appearance, 

 if present, shortly disappears and two layers may be 

 distinguished an inner spicular portion and an outer 

 striated portion. The inner portion is gelatinized first 

 and then the outer becomes thinner, more homogeneous- 

 looking and more nearly transparent until finally it is 

 also gelatinized and only the capsule is left. In the sec- 

 ond method 2 furrows or actual fissures extend trans- 

 versely or obliquely from the hilum to the margin on 

 either side and the material included between them and 

 the hilum and the distal margin loses all its definite 

 structural appearance and becomes a nearly homoge- 

 neous, hyaline-looking mass which is invaded at the 

 margin by short cracks. The starch at the proximal end 

 and sides forms fine striated bands at the margin. The 

 portion distal to the hilum is slowly gelatinized with 

 some swelling but not much distortion, the short fissures 

 or cracks at the margin remaining visible for a long time. 

 The proximal material gelatinizes more slowly but finally 

 only a row of refractive granules remains at the margin 

 which very slowly disappear. 



The gelatinized grains are much swollen and have 

 moderately thick capsules. They are somewhat distorted 

 but retain some resemblance to the form of the untreated 

 grain. 



The reaction with nitric acid begins immediately. 

 Complete gelatinization occurs in but rare grains, less 

 than 0.5 per cent of the entire number of grains and 

 6 per cent of the total starch in 5 minutes; in about 11 

 per cent of the grains and 20 per cent of the total starch 

 in 15 minutes; in about 16 per cent of the grains and 

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

 21 per cent of the grains and 65 per cent of the total 

 starch in 45 minutes ; in about 25 per cent of the grains 

 and 70 per cent of the total starch in 60 minutes. (Chart 

 D263.) 



The hilum is distinct and a bubble is not formed 

 there in any of the grains. The lamella; are distinct at 

 first but later are obscured. Gelatinization begins at, the 

 hilum and proceeds according to three methods. In the 

 great majority of the grains the starch immediately 

 around the hilum, which probably represents a primary 

 starch formation, is split into fragments of varying 

 shape, number, and size, and the portion surrounding it, 

 which probably represents a secondary starch formation, 

 is divided by fine stria?, partially gelatinized and swells, 

 pushing the more resistant part to the margin where it 

 forms a broad, lamellated, coarsely striated, marginal 

 band, around the inner border of which are arranged the 

 segments of the primary starch. These last are very re- 

 sistant, and though they grow progressively smaller and 

 more refractive they usually remain for some time after 

 the rest of the grain is gelatinized. In the marginal 

 band the lamclated appearance shortly disappears and 

 two portions may lie distinguished ail inner, spicular, 

 refractive, and an outer, granular, less-refractive por- 

 tion. The inner segment is gelatinized moderately rap- 



