CHEMICAL BASIS OF PLANT FORMS 253 
vestigations of others. I have introduced these statements, 
selected from a mass of material, as evidences in favor of the 
view stated at the beginning of this paper. 1 My own study has 
been directed towards the discovery of saponin in those plants 
where it was presumably to be found. The practical use of this 
theory in plant analysis will lead the chemist at once to a search 
for those compounds which morphology shows are probably 
present. 
I have discovered saponin in all parts of the Yucca angusti- 
folia, in the Y . filimentosa, and Y.gloriosa ; in several species of 
Agavas, and in plants belonging to the Leguminosae family. 
The list 2 of plants in which saponin has been discovered is 
given in the note. All these plants are contained in the middle 
plane of Heckel’s scheme. No plants containing saponin have 
been found among apetalous groups. No plants have been 
found containing saponin among the lower monocotyledons. 
The plane of saponin passes from the Liliaceae and allied 
groups to the rosales and higher dicotyledons. 
Saponin belongs to a class of substances called glucosides. 
Under the action of dilute acids, it is split up into two sub¬ 
stances, glucose and sapogenin. The chemical nature of this 
substance is not thoroughly understood. The commercial 3 
product is probably a mixture of several substances. 
This complexity of chemical composition of saponin is ad¬ 
mirably adapted for the nutrition of the plant, and it is asso¬ 
ciated with the corresponding complexity of the morphological 
elements of the plant’s organs. According to M. Perrey, 4 it 
seems that the power of a plant to direct the distribution of its 
carbon, hydrogen, and oxygen to form complex glucosides is 
indicative of its higher functions and developments. 
The solvent action of saponin on resins has been already 
1 For further facts confirming this theory, see “Comparative Chemistry 
of Higher and Lower Plants,” by H. C. De S. Abbott, Anier. Naturalist , 
August, 1887. See p. 257. 
2 Different genera and species of the following: Ranunculaceae, Berberi- 
dacese, Carophyllaceae, Polygalaceae, Bromeliaceae, Liliaceae, Smilaceae, Yuccas, 
Amaryllideae, Leguminosae, Primulaceae, Rosaceae, Sapindaceae, Sapotaceae. 
3 Robert, Chem. Ztg. 
4 Compt. Rend., xciv, p. 1124. 
