Similar evidence of tropical conditions comes from the Paris basin where, amongst other plants, numerous palms occur, includ ing Nipa; Ottelia, a tropical water-plant of the Old World is also found. Saporta pointed out the further evidence for tropical con ditions shown by the scarcity of caducous leaves, an absence which indicates the non-occurrence of seasonal changes. The mid dle Eocene of the Bournemouth beds (Hampshire) still shows something of a tropical character. The flora is as yet incom pletely known, but Dr. Helena Bandulska has begun in connection with it, one of the few systematic studies of leaf-cuticles that has been made. Isolated cuticles have frequently been studied, but the systematic examination of living species is but begun. It may prove of great value. The Nipa palm (determined from fruits) flourished, also such tropical genera as Aniba, Litsea and Neo litsea; but somewhat cooler conditions may be evidenced by Lindera and Nothofagus. Gardner and Ettingshausen had pre viously recorded many ferns, also conifers including Araucarites.
We must draw attention to a curious and important fact. It has been noted that the flora of the London clay was exotic. All Ter tiary floras continued to be so in a large degree until towards the end of the period. At first even the families were mainly exotic. Gradually European families came in, but the relationship of the genera was exotic. Then European genera began to appear, but the relationship of the species was exotic. Lastly, at the end of the Pliocene the whole flora was transformed to one of European species. Stated in another way : A flora of European relationship gradually replaced one of exotic relationship, which died out.
The relationship of the dying flora is very remarkable. In the Eocene it was more or less world-wide, but with a marked leaning to plants of the Far East. In floras later than the Eocene the relationship contracts. African affinities nearly disappear. Plants with relations in the Far East predominate. Next in order come North American and Mediterranean plants; then Australian, in spite of the fact that the Far East and America are so far, and the Mediterranean so near. Yet another way of stating the same fact is, that a type of flora which was gradually killed out in Europe, survived largely in the Far East and in America, and only in a very small degree in the Mediterranean. The parts of the Far East in which the living allies are found are Japan, China, Burma, further India, the Malay Peninsula, Malay Islands, Formosa, the Philippines; also Australia. In a general way as time passed the relationship passed northward from Malaya to Japan and China, and from the West Indies through the United States to Canada.
The upper Eocene of Hordle (Hampshire), the flora of which was described by M. E. J. Chandler, has yielded the conifers Sequoia (related to the red-wood) and pine. In addition there
occur among flowering plants such tropical or sub-tropical genera as Broussonetia, Chlorophora, Gordonia, lodes, Meninspermum, Natsiatum, Nipa, Orites, Phellodendron, Symplocos, Zanthoxylon, and various vines. Among genera which now range into Europe are Corydalis, Liquidambar, Styrax, as well as the blackberry, elder and persimmon.
A flora of somewhat the same age is preserved in the Baltic amber. Reference has already been made to its mode of preserva tion. The plants include the amber-pine itself, from which the resin dripped, enclosing insects, leaves, twigs, wood, flowers, seeds and hairs. Many of the flowers closely resemble living forms. Among exotic genera are two palms Phoenix (the date-palm) and Sabal, Clethra, Dalbergia, Deutzia, Ephedra, Hammamalis, Hib bertia, Magnolia, Stuartia, Trianthera and Ximenia. Among Euro pean genera are Daphne, Erodium, Geranium, Loranthus, Amaran tus, Myrica, Smilax and Thesium, besides oak, chestnut, beech, willow, polygonum, flax, maple, holly, buckthorn and wild parsley. Probably this list needs revision. It will be noticed that a great number of these genera have not appeared in previous lists, and will not appear in later ones. The amber flora offers a good example of the selective process which accompanies different kinds of preservation.
One of the largest known fossil floras belongs to the Oligocene, that of Aix in Provence. It was determined by Saporta. It comes from the bed of an old lake. The lake itself long continued in existence, and the life around and within it suffered many vicissi tudes whilst the region was convulsed by the earth movements and volcanic activity of the time, although no very great change took place in the flora from beginning to end. Some of the exotic families represented are Bignoniaceae, Proteaceae and Sapotaceae. Among exotic genera are Aralia, Ailanthus, Bombax, Leucothoe, Magnolia, Sapindus, Sterculia, Zanthoxylon. Several conifers and palms occur. Lauraceae are represented by cinnamons and cam phors. Among European genera are Arundo, Daphne, Smilax and Styrax, bur-reed, bulrush, pond-weeds, alders, birch, oak, fig, pop lar, willow, laurel, jasmine, olive, oleander and persimmon.