It has been discovered that at the beginning of the Eocene the lake of Rilly occupied a vast area east of the present site of Paris; a water-course fell there in cascades, and Munier-Chalinas has reconstructed all the details of that singular locality; plants which loved moist places, such as Marchantia, Asplenium, the covered banks overshadowed by lindens, laurels, magnolias and palms; there also were found the vine and the ivy; mosses (Fontinalis) and Chara sheltered the crayfish (Astacus); insects and even flowers have left their delicate impressions in the travertine which formed the borders of this lake.
Asplenium bulbiferum), produce buds of this character.
Not unlike the runner, though growing in a very different way, are the bud-plants formed on the fronds of several kinds of ferns belonging to the genera Asplenium, Woodwardia, Polystichum, Lastrea, Adiantum, Cystopteris, &c. In some of these (Adiantum caudatusn, Polystichum lepidocaulon) the rachis of the frond is lengthened out much like the string of the strawberry runner, and bears a plant at its apex.
In others again (Woodwardia orientalis, Asplenium bulbiferum), buds are numerously produced on the upper surface of the fronds.
Hardy British ferns belonging to such genera as Asplenium, Nephrodium, Aspidium, Scolopendrium, have become fairly popular of late years, and many charming varieties are now used in borders and rockeries.