REACTION-INTENSITIES WITH EACH AGENT AND REAGENT. 



171 



were entirely gelatinized. In Narcissus iazetta grand 

 monarque, during the first 15 minutes less than 0.5 per 

 cent of the grains, but 20 per cent of the total starch, 

 were gelatinized, and during the progress of the reaction 

 both curves rise, but the curve of the percentage of total 

 starch rises somewhat more rapidly than the other. la 

 certain of the charts this progressive separation is seen, 

 as in Amaryllis belladonna (Chart D 635) and Tritonia 

 pottsii (Chart D 651) ; in others, there is for a time 

 separation, this being followed by approximation, as in 

 Hippeastrum titan (Chart D 636) and Hcemanthus puni- 

 ceus (Chart D 640) ; and in others, there is an early 

 marked separation followed in time by approximate 

 parallelism, as in Gladiolus tristis (Chart D 650) and 

 Calanthe rosca (Chart D 658), and so on with various 

 differences. 



While no two charts are identical some are quite 

 similar, yet readily differentiated. Such similarity is apt 

 to be found in very closely related varieties and species 

 for instance, in Hippeastrum titan, H. ossultan, and 

 H. dceones (Charts D636, D 637, and D638), and in 

 Iris (Charts D 646, D 647, and D 648). Those of the 

 several species of Lilium differ markedly (Charts 

 D 643, D 644, and D 645). Those of widely separated 

 species, such as Hcemanthus katherina; and //. puniceus, 

 are decidedly different from each other, which species for 

 reasons as stated, probably represent subgeneric groups. 

 The same peculiarities are true in Iris, those of /. iberica 

 (Chart D646), I. trojana (Chart D 647) and I. cen- 

 gialti (Chart D 648) having a close general resemblance, 

 and markedly contrasted with the curves of the appa- 

 rently distantly related I. persica var. purpurea (Chart 

 D 649), which curves are quite different from the former. 

 Gladiolus and Tritonia (Charts D 650 and D 651), while 

 representing closely related genera and exhibiting at the 

 end of the 60-minute period the same percentages of 

 both total starch and entire number of grains completely 

 gelatinized, nevertheless present differences in the courses 

 of the curves that are quite definitely distinctive. 



In some of the charts it will be seen that there is an 

 early period of resistance of the starch to gelatinization. 

 This is manifest in some instances in the percentage of 

 completely gelatinized grains, but not in the percentage of 

 total starch gelatinized, as in Iris iberica and /. trojana 

 (Charts D 646 and D 647), and in Lilium chalcedonicum 

 (Chart D 645) ; in others, it may be the reverse, as in 

 Narcissus tazetta grand monarque (Chart D642) ; and 

 in others, in both percentages, as in Amaryllis bella<- 

 donna (Chart D 635) and Hippeastrum titan (Chart 

 D 636). In other charts both curves may begin at once 

 to rise rapidly, but the percentage curve of total starch 

 rises more rapidly than the other, as in Hcemanthus 

 puniceus (Chart D640), L. martagon (Chart D643), 

 Musa arnoldiana (Chart D 654), and Miltonia vexillaria 

 (Chart D 656). In the different starches these changes 

 go on with varying rapidity and relationships, so that 

 by the end of the 5-minute period not only may the 

 two curves of any given starch be well separated but their 

 courses may be quite different. Thus, the figures for the 

 percentages of total starch and number of grains com- 

 pletely gelatinized in 5 minutes in the above four species 

 are 33 and 65, 30 and 77, 30 and 86, and 27 and 50, 

 respectively. It is to be noted that while in the four cases 

 the percentages of the entire number of grains com- 



pletely gelatinized are the same or nearly the same, the 

 percentages of total starch are in all distinctly different. 

 This is of diagnostic importance because it indicates 

 inherent individual peculiarities of the several starches. 

 The preceding groups of charts indicate to what degree 

 the reactions of different starches with a given reagent 

 may differ in the percentages of both total starch and 

 entire number of grains completely gelatinized, and also 

 the tendencies in general to similarities of the pair of 

 curves of closely related starches and to dissimilarities 

 of distantly or unrelated starches. 



When similarities are observed, as in the very closely 

 related Hippeastrums, such peculiarity is to be expected 

 in the reactions of the same starches with other reagents. 

 For instance, in the reactions with chloral hydrate 

 (Charts D 659, D 660, and D 661) the three pairs of 

 curves are closely alike, the type of curve is the same as 

 is seen in the pyrogallic-acid reactions (Charts D 636, 

 D 637, and D 638), but the positions of the curves in the 

 two reactions are different, owing to the distinctly lower 

 reactivities of these starches with chloral hydrate. When, 

 however, the reactions of the starches of well-separated 

 or unrelated species are studied it is found that there 

 may be the widest variations in the relationships of the 

 two curves, not only with different agents but also with 

 the same reagent, even to the extent that the percentage 

 of total starch gelatinized will give a type of curve 

 entirely different from that of the percentage of grains 

 completely gelatinized. Thus, examining the pyrogallic- 

 acid reactions of the various starches (Charts D 635 to 

 D658), it will be found that there is with few excep- 

 tions a well-marked tendency to separation of the two 

 curves, and that in some instances the two curves are 

 not of the same type, as in Lilium chalcedonicum (Chart 

 D 645) and Iris trojana (Chart D647). In contrast 

 with this, in the chloral-hydrate reactions (Charts D 659 

 to D 667) both curves tend to marked closeness in course 

 and hence to the same type. Comparisons of the pyro- 

 gallic-acid and chloral-hydrate reactions of the same 

 starch bring out many interesting points. For instance, 

 in Amaryllis belladonna (Charts D 635 and D 662) in 

 the pyrogallic-acid reaction the two curves become widely 

 separated during their progress, the percentage of com- 

 pletely gelatinized grains ceases to increase after 30 

 minutes, but the quantity of gelatinized starch is mate- 

 rially being added to by the grains that are undergoing 

 partial gelatinization ; while in the chloral-hydrate reac- 

 tion the curves keep very close throughout. The most 

 marked difference between the reactions of the two rea- 

 gents is seen in the curves of the percentage of the entire 

 number of grains completely gelatinized, which differ 

 greatly, while the total percentage curves differ compara- 

 tively very little. In Hcemanthus puniceus (Charts 

 D 640 and D 664) the pyrogallic-acid and chloral-hy- 

 drate curves are of different types; and the curves of 

 both pairs of percentages tend to closeness, more particu- 

 larly the chloral-hydrate curves. In Narcissus tazetta 

 grand monarque (Charts D 642 and D665) both pairs 

 are again different, not only from those of the preceding 

 charts, but also from each other, and as markedly in the 

 latter as in the former case. Here the types of the pairs 

 of curves are distinctly different, and while the two 

 curves in the pyrogallic-acid reaction tend to progressive 

 separation, those of the chloral-hydrate reaction tend to 



