254 PLANT AND ORGANIC CHEMISTRY 
discussed. Saponin likewise acts as a solvent upon barium 1 
sulphate and calcium 2 oxalate, and as a solvent of insoluble 
or slightly soluble salts would assist the plant in obtaining 
food otherwise difficult of access. 
Saponin is found in endogens and exogens. The line di¬ 
viding these two groups is not always clearly defined. State¬ 
ments pointing to this are found in the works of Heckel, 
Bentham, and others. 
Smilax belongs to a transition class, partaking somewhat of 
the nature of endogen and of exogen. It is worthy of note 
that this intermediate group of the sarsaparillas should con¬ 
tain saponin. 
It is a significant fact that all the groups above named con¬ 
taining saponin belong to Heckel’s middle division. 
It may be suggested that saponin is thus a constructive ele¬ 
ment in developing the plant from the multiplicity of floral 
elements to the cephalization of those organs. 
It has been observed that the composite occurs where the 
materials for growth are supplied in greatest abundance, and 
the more simple forms arise where sources of nutrition are re¬ 
mote. We may gather from this fact that the simpler organs 
of plants low in the evolutionary scale contain simpler non- 
nitrogenous chemical compounds for their nutrition. 
The presence of saponin seems essential to the life of the 
plant where it is found, and it is an indispensable principle in 
the progression of certain lines of plants, passing from their 
lower to their higher stages. 
Saponin is invariably absent where the floral elements are 
simple; it is invariably absent where the floral elements are 
condensed to their greatest extent. Its position is plainly that 
of a factor in the great middle realm of vegetable life, where 
the elements of the individual are striving to condense, and thus 
increase their physiological action and the economy of parts. 
It may be suggested as a line of research to study what are 
the conditions which control the synthesis and gradual forma- 
1 Bui. de la Soc. Chim. 
2 “Yucca Angustifolia,” Trans. Am. Philos. Soc., December, 1885. See 
p, 126. 
