Three scientists are credited with the development of cell theory. Matthias Schleiden observed that all plants were made of cells; Theodor Schwann observed that all animals were also made of cells; and Rudolf Virchow observed that cells only come from other cells.
I think it might be the first one: hiv infections. (hope this helps!)
The following which poses as the most logical conclusion about the life cycle of this plant is definitely : The plant is a fern, and the gametophyte is its dominant phase. I am pretty sure you will fing this answer interesting. Regards!