PHYLOGENY OF THE ANGIOSPERM. There can be no doubt that the Angiospermx, have been derived from the Pteridophyta ; but it is a question whether they have had an independent origin from that group or whether they are to be traced back to it through the Gymnosperms. In view of the wide gulf which separates the Angiosperms from even the highest Pteridophyta, and of the affinities of the Gymnosperms to the Ptcridophyta on the one hand and to the Angiosperms on the other, the latter suggestion would appear to be the more probable.
Although the Monocotyledons and the Dicotyledons have so many features in common, it is probable that they have not had the same origin. The Gymnospermous forms to which the Dicotyledons are most nearly allied are the Coniferie, and Gnetunz among the Gnetaecle. The marked Angiospermous characters of Gnetion, and its general similarity in habit to a Dicotyledonous plant, afford some ground for regarding this genus as the starting-point of the Dicotyledons. But tumors probably the Dicotyledons are to be traced hack to the Conifera% and the Clnetaceae to be regarded as a lateral offshoot of the Confferra, with an Angiosperrnous tendency, but not leading on to higher forms. The Gymnosperms which most resemble the Ai onocotyludons are the Cycadacex; and, if it be assumed that the Angiosperms have sprung from the Gymnosperms, it is to this order of the latter class that the Monocotyledons are to be traced. The Monocotyledons in which this resemblance is most e.onspicuous are those, such as the .Aroids and Palms, which belong to the series IN-nth:flora%
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