NOTES AND >\< \\ -!..\ 





arc the wiinc I. ut modified in their applicat rUin 



inii-Ttant respects. In l">th investiirations 



< iodine ami aniline r>a lion*, and 

 tin 1 gelatinixation ri a< lions with heat and \anotij, r 

 cal reap : 



in tlu- in. ill- 1 <>f record i ni; the reactions with the chemi- 

 cal reagent.*, an<l in tin- kinds and concentrations 

 reagent*. In the form, r re-, arch tin- qu.intu 

 fercntiation- |.\ means of the chemical reagents were 

 made by determining the time of the : ooni- 



r pra.ti.ally complete gelatioization, ami the 

 prcp.i tin- rva. nut ade- 



.(uat.lv protected from the air and evaporation. It was 

 found 'iur.!..,' the progress of tin* work that fictitious 

 values may lie recorded owing to the existence in nearly 



form of March of dilTerciit kind* of grain* which 

 vary in proportions ami gclutinizabilities. together with 

 varying decrees of influence of the air (probably chiefly 



ly differences in oxidation), and effects that are 



due U> varying rapidity and degrees of evaporation. 



Such sources of falla. y illy eliminated 



in tlie pr. - t research by making records of the progress 



of gclatini/ation in regard to both tlie entire nuraU-r of 



grains completely gelatinized and the |>ercentage of the 



latinized at definite time-int.Tvala; and 



prevention nf oxidation and evaporation by seal- 



lie preparation^. In nearly every form of starch 



there are grains, usually very small, and also part* of 



graii i quite reistant to reagents. The former 



i. mmonly represent much less than '> per cent of the 



quantity of starch, and it has been assumed that 



L'e|atim/at'..'li letc when It.") |MT i 



the total March hu- The methods used 



and their values in the differentiation of starches have 



rtii in full in the preceding memoir on pages 



Kt, and supplementary statements are to be 



found in the present memoir in Chapter* II. IV. and V. 



Tl :ic method employed in this research is 



the same in all respects as in the prcivding investigation, 

 in tin- rejwrt of which it has been discussed with suffi- 

 cient fulness (page .')<>? ). Its value ha. not only been sub- 

 stantiated hut accentuated by the results of the present 

 ,-tiiilv of : | parent- and hybrid-stocks. 



The jxilari-i-opic, iodine, and aniline methods are so 

 crude that the jxTsonal equation enters largely into the 

 determination of the values recorded, and while they 

 have proved of u able usefulness they are so 



inferior t<> the geJatinization method that they should 

 .en a very MiUinlinate place. The polarization and 

 aniline im-tlmd. are by fur ' of all o' 



he anilines will be found of much value in the 

 differentiation of different lamella? of individual grains, 

 as h:i own h\- the work of Denniston (see pre- 



Meinoir, page "><). Iiniino. like the anilines, can 

 be nv it advantage in the studv of the -trudnre 



of the starch prain. It is aim of usefulness by showing 

 Iiy variation- in the color re.ntioii- differences in the 

 constitution of starches from different sources; of dif- 

 ferent kinds of grains of the same starch ; of the capsular 

 and intracapsular parts of the grains; anfl of the cap- 

 sules themselves. The method used in determining the 

 temperature of gelatinizti< act, as has 



been shown by the fact that when the experiments are 

 made with proper care the figures recorded are quite as 



uniform as t!i M . obtained in the determination of lot 

 melting-points of various substance*. 



The gelatinization method by means of various 

 i -henncal reagents as here pursued has proven to be so 



that the records of I experiment* 



ry rarely, been found to be exactly or prac- 

 tically exactly the same, even though made at widely 

 > ami with varying temperature and 

 hum; \ rarely, for HOtt inexplicable reason, a 



markedly aberrant n-o>rd has been i 

 every instance this error was detected because of 

 absence of agreement with what was 



editions. In fac<. as was found < and as 



will be obvious by the context, the records of the re.i 

 obtained by means of the various I arc 



in the case of each agent an . ami of all c. 



lively, in a very huge measure checks upon each other. 

 In other words, the values for the starch of a given spe- 

 cies serve as prototype or generic standard with v 

 the records of all other species and varieties of the genus 

 inn t conform, unless there are represented members 

 of subgenera or other subgeneric divisions. The closer 

 botanically the sjx-cies or the varieties the closer will 

 the records collectively agree with the given standard. 

 Varieties of a species exhibit remarkable closeness, and 

 their values represent a species type. V ibers 



of subgenera or other form of subgeneric division are 

 represented they may exhibit differences that are as 

 marked, and even more marked, than those of members 

 of closely related genera. 



(~Tt is to be borne in mind that the method of classi- 

 fication of the systematist is of an arbitrary chan 

 as is evident, for instance, in the shifting of species from 

 one to another genus, the remodeling of genera, families, 

 etc. This classifying and reclassifying that has been in 

 progress for generations continues at the present time, 

 and even now the most generally accepted classification 

 can not be accepted as being more than tentative. If, 

 therefore, the results of these investigations seem to be 

 or are not in accord in isolated instances with the classi- 

 fication of the systematist it docs not follow that the 

 former are wrong. As evidence of the mutual checking 

 of the records one need examine only the very similar 

 curves of the starchc* of the clow-ly related members of 

 /rvTjn'tarts E 30 to K 33) and llir'l,ar,lia (Ch.. 

 the dissimilar curves of the starches of members of 

 subgcneric divisions, such as the hardy and tender 

 species of Crintim (Charts ' the dissimilar 



curves of the starches of members of subgenera of Be- 

 nonia (Chart- Ur curvns of 



arches of the closely related genera /( maryf/i* and 

 Hrun.*i-i'ji>i (Chart ]'. I), and of ami 7V. 



(Charts E 34 and E3.1); and the dissimilar curve*, 

 usually highly characteristic, of the starches of various 

 ime and different families that are shows 

 in this series of charts (El to E 46), as a whole. These 

 similsrities and dissimilarities are in degree variable in 

 accordance with what in general should be expected, or 

 what is at least in accord with unquestionable botanical 

 classification. 



The differentiation of starches br heat, as in tile 

 temperature of gvlatinization method, is to be recom- 

 mended s- ' much value, both quantitatively and 

 qualitatively. It was shown in the preceding invest!- 



