Evolutionary history of plants and radially symmetrical, is an integumented megasporangium surrounded by a cupule. The megasporangium bears an unopened distal extension protruding above the multilobed integument. It is suspected that the extension was involved in anemophilous pollination. "Runcaria" sheds new light on the sequence of character acquisition leading to the seed. "Runcaria" has all of the qualities of seed plants except for a solid seed coat and a system to guide the pollen to the ovule. The first spermatophytes (literally: "seed plants") – that is, the first plants to bear true seeds – are called pteridosperms: literally, "seed ferns", so called because their
The Variation of Animals and Plants under Domestication spite of the fact that a considerable number of these assumptions are untenable, a part of the theory still remains which must be accepted as fundamental and correct,--in principle at any rate,--not only now but for all time to come. ... presupposing the existence of material particles in the germ which possess the properties of the living being ... I must honestly confess to having mentally resisted this fundamental point of the Darwinian doctrine for a long time." The Variation of Animals and Plants under Domestication The Variation of Animals and Plants under Domestication is a book by Charles Darwin