REACTION-INTENSITIES WITH EACH AGENT AND REAGENT. 



171 



were entirely gelatinized. In Xarcittut tazetta grand 

 monarqut. during the first 15 minutes leas than 0.5 per 

 cent of the grain.*, hut .'" JXT .-.-nt of the toUl starch, 

 were gelatinized, and during the pragma of the reaction 

 i-.th cunes rise, but the curve of the percentage of total 

 itarch rises somewhat more rapidly than the other. In 

 certain of the charts thin progressive separation is seen, 

 as in Amaryllis brlltulunna (Chart 1)635) and TYi'/unta 

 polLtii (Chart I '..' I i ; in others, there is for a time 

 separation, this UMII,' f..ll",-,l by approximation, as in 

 Hifi/if ii.it rum titan (Chart 1> ':!') aiul Ilifinanthus puni- 

 criu (Chart HtMO); and in others, there is an early 

 marked separation followed in time by approximate 

 parallcliMii. an in Gladiolus trittit (Chart 1)650) and 

 Catanlhe rotea (Chart D658), and so on with various 

 differences. 



While no two charts are identical some are quite 

 Minilar. yet readily differentiated. Such similarity is apt 

 to be found in very closely related varieties and species 



nstance, in /A'/>/>r<ufrum titan, II. ostultan, and 

 //. dooms (Charts D636, D637, and D638), and in 

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

 several species of I.iiium differ markedly (Charts 

 and D 645). Those of widely separated 

 species, each as Hirmanthus katkerina and //. punicrus. 

 are decidedly diiT.-r. nt from each other, which species for 

 reasons as stated, probably represent subgeneric groups. 

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

 (Chart in; 10), /. trojana (Chart D647) and /. cen- 

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

 and markedly contrasted with the curves of the appa- 

 rently distantly related /. pertica Tar. purpurra (Chart 



' i , which curves are quite different from the former. 

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

 representing closely related genera and exhibiting at the 

 em! of the 60-minute period the same percentages of 

 'th total starch and entire number of grains completely 

 L'I l.itun.v,!. iii-v.-rtheleas 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. 



is manifest in some instances in the percentage of 

 completely gelatinized grains, but not in the percentage of 

 total starch gelatinised, as in Iris ibenca and /. trojana 

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

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



ntut tairtla grand monarque (Chart D642) ; and 

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

 donna (Chart D635) and Hippeastrum titan (Chart 



'). In other charts both curves may begin at once 



v rapidly, but the percentage curve of total starch 

 rises more rapidly than the other, as in Hcemanthus 

 puniceus (Chart D640), L. martagon (Chart DC.l.ti. 

 MUM arnoltiiana (Chart D 654), and MUtonia vexUlaria 

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



Kon with varying rapidity and relationship*. w> that 

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

 two curve* of any given starch be well separated hut 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- 



... 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 larches. 

 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 aii<l 

 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. 



\\lien similarities are observed, as in the very closely 

 related Hippeastrums, such jnvuliahty is to be expected 

 in the reactions of the same starches with other reagents. 

 Fur instance, in the reactions with chloral hydrate 

 (Charts D659, D660, and D661) the three pain of 

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

 is seen in the pyrogal lie-acid reactions (Charts DC36, 

 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 agenta 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 1) G35 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 

 D645) 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 game 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 D635 and D662) in 

 the pyrogallic-acid reaction the two curves become widely 

 separated during their progress, the percentage of M.III- 

 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 curve* differ compara- 

 tively very little. In Ilcemanthu*. punifrus (('harts 

 D640 and D664) 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 \arcis*us tazrtta 

 grand monarque (Charts D 648 and D665) both pair* 

 are again different, not only from those of the preceding 

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

 Utter 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 



