Starches in Relation to Genera, Species, etc. 45 



32 (728) 



The differentiation and specificity of starches in relation to genera, 

 species, etc. : stereochemistry applied to protoplasmic proc- 

 esses and products, and as a strictly scientific basis 

 for the classification of plants and animals. 



By Edward Tyson Reichert. 



[From the S. Weir Mitchell Laboratory of Physiology, University of 



Pennsylvania.] 



Under the foregoing title the results of an elaborate investiga- 

 tion will shortly appear as Publication No. 173 of the Carnegie 

 Institution of Washington. This research is supplementary and 

 complementary to, and in support of, Publication No. 116 entitled, 

 "The Differentiation and Specificity of Corresponding Proteins 

 and Other Vital Substances in Relation to Biological Classification 

 and Organic Evolution: The Crystallography of Hemoglobins." 

 A preliminary review of the latter will be found in the Proceed- 

 ings of the Society, 1908, V, 66-68. 



Studies of the histological, physical, physico-chemical and 

 chemical properties of over 300 starches from various plant-sources 

 were made. Among the most important conclusions reached are 

 the following: 



1. Starch is not a unit substance but exists in a vast number of 

 stereoisomeric forms. Starch from any given plant and of every 

 mature starch grain is a mixture of different forms of starch- 

 substance. 



2. Starches from different plants exhibit constant and specific 

 characters in relation to genera, species and varieties, by which 

 the plant can be identified. 



3. The stereochemic peculiarities of starches and other complex 

 organic metabolites constitute a strictly scientific basis for the 

 classification of plants and animals. 



