Date of this Version
It is unnecessary for me to state at the outset what is evident to every botanist, that it is as yet impossible to present a complete phylogeny of the angiosperms. Phytopaleontology is too young a science, and the materials with which it deals are yet far too scanty to have given us direct evidence as to the phylogeny of all families of plants. No one can trace with great certainty from the fossil remains of plants yet discovered the genealogy of any considerable portion of the vegetable kingdom. It will be many a year before the direct evidence we so much desire will leave no considerable gaps to be filled by skillful interpolation. However, after malting all due allowance for the imperfection of the record, there are many facts as to past vegetation which are well established. Thus, we know that the earliest plants were simple, homogeneous-celled, aquatic organisms. We know that ferns and gymnosperms preceded angiosperms. We know that the angiosperms which first appeared were of lower types, and that the highest types known today were wanting until very late in geological time.