Page:Evolution of Life (Henry Cadwalader Chapman, 1873).djvu/141

Rh (Selaginella, Cypress) is two-leaved, or dicotyledonous; finally, there must be added to these facts the additional one of the Cycadae and Coniferae being outside growers, and of a similar exogenous mode of growth being seen in Isoetes among the Lycopodiaceae. The Lycopodiaceae are, therefore, so closely and intimately allied with the Cycadae and Coniferae that the question naturally arises, Does there really exist in Nature such a distinction as that of Flowerless and Flowering plants? The reproductive apparatus of the Lycopodiaceae is so similar to that of the Cycadae and Coniferae that it is impossible to say where the Flowerless plants end and the Flowering begin. In the first page of this chapter we used purposely the expression, translating Cryptogamia "flowerless," Phanerogamia "flowering." The word cryptos, literally translated, is "obscure," "concealed;" phaneros, "apparent," "evident;" gamos referring to the organs of reproduction. Translating literally, the Cryptogamic plants are those in which the reproductive organs are not absent, but only obscure; the Phanerogamia, those in which the reproductive organs are very evident in the form of flowers. The difference between the higher Cryptogamia and Phanerogamia is not one of kind, but only of degree, the apparent gulf between these two divisions being bridged over by the Lycopodiaceae, Cycadae, and Coniferse. The Linnaean classification is the best yet offered, expressing the real nature of plants. The Angiospermae, as previously stated, are those flowering plants whose seeds have a seed-vessel: their embryo is either Monocotyledonous or Dicotyledonous. The one-leaved or Monocotyledonous form of embryo is universally associated with the endogenous, or inside mode of growth, usually with a threefold arrangement of leaves. The Dicotyledonous or two-leaved embryo, on the contrary, characterizes all outside growers or Exogens, accompanied usually with a fivefold arrangement of leaves. The Monocotyledons include the Palms