CHAPTER V. 



A SYSTEMATIC SUMMARY OF THE GROSS HISTOLOGICAL PROPERTIES OF 

 STARCHES FROM VARIOUS SOURCES. 



NAGEU'S CLASSIFICATION OF STARCHES FROM DIFFERENT SOURCES. 



Nageli, in his elaborate memoir on Die Stiirkekorner {loc. cit.), recorded the results 

 of the histological examinations by Raspail, Payen, Soubeu'an, Schleiden, Bischoff, Criiger, 

 Walpers, Berg, Miinter, Fritzsche, Harting, and others, including liis own observations, of 

 over 1200 starches from different sources. These starches he arranged in 3 classes, 5 sub- 

 classes, and 17 types. As this publication has long since been relegated to the anti- 

 quaria, as virtually no notice is to be found in recent works of this part of his vQvy laborious 

 investigations, as the memoir is a rarity even in the largest of our libraries, and as this 

 data has especial importance apropos of the present research and is of general botanical 

 and biological interest, it seemed very desirable to include these valuable records in the 

 present memoir. In recent literature a large number of descriptions of the forms of different 

 starches will be found, but as such publications are generally readily a^'ailable these refer- 

 ences have not been included. The following text is a free translation of Chapter XII, almost 

 in its entirety, of Nageli's memoir; but many changes have been made in the Latin names, 

 in part in the correction of typographical errors, and in part to bring the matter up to date. 



Nageli states that the different types of starch-grains merge almost imperceptibly 

 into one another, and therefore that the boundaries are necessarily arbitrary ones; and, 

 moreover, that very similar starch-grains are often placed far from one another in the 

 different types. The author states that the grains might always have been arranged 

 systematically within the individual classes according to their shape and structure, but 

 that such a comparative classification would scarcely be possible without a complete col- 

 lection of microscopical preparations. He therefore thought it better to make a classifica- 

 tion according to other principles. In each group the seeds were considered separately 

 from other parts of the plants and the latter were enumerated in systematic order. The 

 natural relationships often determined to what type the grains belong. Tiius, the starch- 

 grains from all the Bromus seeds, although rather varied, are placed together; the grains 

 of the seeds of Alismacece are classified in one type, while those of Butomacece are placed 

 in another, although their grains in general are very similar. Even if the starch of the 

 species of one order completely agrees with that of the other order they are thus classified, 

 because on the whole the grains of Alismacece follow more closely a given type, and those 

 of Butomacece another type. It follows from this, he states, that the descriptions are 

 somewhat more diffuse, less sharply drawn, and correspondingly less diagnostic than they 

 would be in case of a comparative systematic arrangement. They have throughout not 

 the significance of differential characters, and this the less so since it has not been deter- 

 mined which are specific and which are merely individual characteristics. Especial con- 

 sideration has been given to the relative size, mostly to linear dimensions. 



The following is NJigeU's classificatiou of stanshes from different sources: 



A. Grains Simple. 



I. Centric. Hilum in the mathematical center; lamellic always equal at two corresponding 

 diametrically opposite i)oints. 

 Type 1. Spherical. When the grain is free both hilum and grain are spherical. 



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