340 DIFFERENTIATION AND SPECIFICITY OF STARCHES. 



leaves of D. myoporoidcs yield hyoscyamine (C17H23NO3), but the young leaves scopolamine 

 (Ci7H;,N04), alkaloids that are closely related chemically and physiologically. Whether 

 or not the difference in the product of the old and new leaves is owing to a chemical trans- 

 formation of the scopolamine into hyoscyamine, or to a change in the protoplasmic mechan- 

 ism incident to development, or to some other obscure condition, is entirely speculative, 

 yet this instance (coupled with the foregoing, and to which others might be added) is 

 highly suggestive of the plasticity of such substances and of protoplasm, and hence of the 

 exceedingly important results that may be expected in the modifications of stereoisomers 

 by hybridization. 



GENERAL APPLICATIONS OF THIS RESEARCH IN SYSTEMATIC BOTANY. 



It follows, as a corollary from the foregoing data, that upon the basis of intramolec- 

 ular and intermolecular peculiarities of starches, plants can be classified by means not only 

 of the modifications that are observed in their metabolites, as are manifested in the gross 

 macroscopic forms, such as the leaves, flowers, roots, sexual organs, etc., but also by means 

 of the molecular characters of products which are passive, non-structural constituents 

 of the plant. It will be observed that while the findings of this research are in general 

 in correspondence with the recognized classifications of the systematic botanist obtained 

 by means of macroscopic and microscopic methods, they also are in harmony with the 

 shifting of species from one genus to another, and in the remodeling of classes, famiUes, etc., 

 that is continually going on ; and that by the aid of the peculiarities of such metabolites as 

 starch it is manifest that a logical, practically permanent, and scientific classification of 

 plants can be established. For instance, Galtonia candicans was for years known as Hya- 

 cinthus candicans and referred to the genus Hyacinthus. It is clear from the reaction curve 

 that its assignment to another genus is correct, and judging from the peculiarities of the 

 reaction curves it stands between the hyacinths and the members of the tulip tribe. Many 

 plants known years ago as species of Amanjllis have since been moved to other genera, 

 as for instance (among plants represented in this research) Hippcastrum cquestre and H. 

 auHcum, Sprekclia formosissima, Sternbergia lutea, Vallola purpurea, and Zephyranihes Can- 

 dida, all of which have been or are recorded as being corresponding species of Amaryllis. 

 It will be seen, by examining plates 51 to 54 and charts 241 to 246, inclusive, and 252, 

 that while all of the starches have in common the same gross fundamental histological 

 characters, the reaction curves show quite clearly that not one could be mistaken for a 

 species of Amaryllis. Likewise, some of the Crinums have been designated Amaryllis, 

 but it will be noted by an examination of charts 241 and 242 that the generic pecidiar- 

 ities of Crinum are quite distinct from those of Amaryllis. Likewise, Tritonia and Mont- 

 bretia have been confused: Tritonia pottsii was named by Baker Montbretia pottsii; T. 

 crocosynceflora is a hybrid of T. pottsii X pollen of Crocosmia aurea, also known as T. aurea 

 Pappe. Comparing the forms of the grains of the six specimens of Tritonia studied in this 

 research, it ^vill be noted that the grains of T. crocata and T. securigera have in common 

 certain features wliich distinguish them from T. pottsii and its hybrid, which in turn have 

 some characteristics in common. An examination of the reaction-curves will show this same 

 grouping very strikingly, the curves of the first and those of the last corresponding. The 

 differences are so marked that it would seem that T. pottsii is misclassed. T. securigera 

 has been known as Gladiolus securiger, but while the starch-grains have general character- 

 istics in common with those of Gladiolus a comparison of the reaction-ciu'ves indicates 

 clearly that its grouping as a Tritonia is correct. 



Again, there has been a shifting of Tritonias and Ixias, and here too, wliile the gi'ains 

 belong to the same class so far as their shapes are concerned, the reaction-curves are dis- 

 tinctly unlike, so much so that there should not be any difficulty in distinguishing the 

 members which strictly belong to one genus from those of the other. Tritonias and Free- 



