1 70 PLANT AND ORGANIC CHEMISTRY 



gauge the progression or retrogression of a plant, species, or 

 genus, and would accentuate the characters of progression, 

 adaptation, and filiation. 



5. Variations in chemical constituents would be detected by 

 analysis earlier than consequent variations of organs or tissues. 



6. It is a law of internal influences controlling function and 

 modifying forms rather than of external forces, hence a study 

 of the elements of the innermost structure of plant life is a 

 study of that law and of life itself. 



No/t all chemical constituents will answer as means of clas- 

 sification for the same great evolutionary plane, though any 

 compound might be found to furnish a basis for the division 

 of plants into classes, orders, sub-orders, genera, and species. 



Albuminous compounds and chlorophyll are less likely to 

 be serviceable as compounds of classification. They are inti- 

 mately associated with the manifestation and continuance of the 

 conditions of life, though they are not regarded as the essen- 

 tial factors in development. 



The chemical study of plants is meant to include micro- 

 chemistry in its application to histology and physiology, in de- 

 termining the position in the cell of any chemical compound, 

 and qualitative and quantitative analysis to be practiced in 

 accordance with the schemes of Dragendorff and others. I 

 should suggest that analysis be made of each part of the plant, 

 as of the root, stem, bark, wood, leaf, flower, and seeds; also 

 of the separate organs of plants, i.e., in the flower, of the sta- 

 mens, pistils, petals, calyxes, and of various plants under 

 various conditions of age, climate, soil, and seasons. Under 

 these conditions a comparison of chemical constituents with 

 plant structure would lead to a comprehension of the corre- 

 lation between morphology and chemistry. 



