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 The Variation of Animals and Plants under Domestication The Variation of Animals and Plants under Domestication is a book by Charles Darwin that was first published in January 1868. A large proportion of the book contains detailed information on the domestication of animals and plants but it also contains in Chapter XXVII a description of Darwin's theory of heredity which he called pangenesis. Darwin had been working for two years on his "big book" on Natural Selection, when on 18 June 1858 he received a parcel from Alfred Wallace, who was then living in Borneo. It enclosed a twenty pages