On plane 2 plants which have a multiplicity of floral elements, as the many petals and stamens of the rose; and finally, the higher plants, the orchids among the monocotyledons and the composite among the dicotyledonous plants, come under the third division of condensation of floral elements. It will be impossible to take up in order for chemical consideration all these groups, and I shall restrict myself to pointing out the occurrence of certain constituents. I desire now to call attention to chemical groups under the apetalous plants having simplicity of floral elements. _Cassuarina equisetifolia_[20] possibly contains tannin, since it is used for curing hides. The bark contains a dye. It is said to resemble _Equisetum_[21] in appearance, and in this latter plant a yellow dye is found. The _Myrica_[22] contains ethereal oil, wax, resin, balsam, in all parts of the plant. The root contains in addition fats, tannin, and starch, also myricinic acid. In the willow and poplar,[23] a crystalline, bitter substance, salicin or populin, is found. This may be considered as the first appearance of a real glucoside, if tannin be excluded from the list. The oak, walnut, beech, alder, and birch contain tannin in large quantities; in the case of the oak, ten to twelve per cent. Oak galls yield as much as seventy per cent.[24] The numerous genera of pine and fir trees are remarkable for ethereal oil, resin, and camphor. The plane[25] trees contain caoutchouc and gum; peppers,[26] ethereal oils, alkaloids, piperin, white resin, and malic acid. _Datisca cannabina_[27] contains a coloring matter and another substance peculiar to itself, datiscin, a kind of starch, or allied to the glucosides. Upon the same evolutionary plane among the monocotyledons, the dates and palms[28] contain in large quantities special starches, and this is in harmony with the principles of the theory. Alkaloids and glucosides have not yet been discovered in them. Other monocotyledonous groups with simplicity of floral elements, such as the typhaceae, contain large quantities of starch; in the case of _Typha latifolia_[29] 12.5 per cent., and 1.5 per cent. gum. In the pollen of this same plant, 2.08 per cent. starch has been found. Under the dicotyledonous groups, there are no plants with simplicity of floral elements. Returning, now, to apetalous plants of multiplicity and simplification of floral elements, we find that the urticaceae[30] contain free formic acid; the hemp[31] contains alkaloids; the hop,[32] ethereal oil and resin; the rhubarb,[33] crysophonic acid; and the begonias,[34] chicarin and lapacho dyes. The highest apetalous plants contain camphors and oils; the highest of the monocotyledons contain a mucilage and oils; and the highest dicotyledons contain oils and special acids.