FORMS. Fossil remains of Conifers, consisting. of branches, leaves, cones, and seeds, are found in great abundance in the most recent of the Mesozoic and in the Tertiary formations, and have been referred to genera still living on account of their resemblance to them. But only when such determination is based on well-pre served cones may it, as a rule, be considered sat isfactory. Leaves and leaf-bearing branches fur nish only in exceptional eases a basis for the determination of the genera, as there arc recent genera from different families in which the leaf ing branches cannot be distinguished at all by their outward appearances.
It is no better with the fossil woods, for it is known that fragments of wood having the struc ture of living conifers are found in every state of preservation throughout the entire series of geologic formations from the Middle Devonian upward. The great hopes entertained that they would furnish important results have. according to Solms-Lanbaeh, not materialized, owing to the uniformity of structure which characterizes sec ondary growth in thickness in Conifers. More over, the Cordaites, which stand between the and Conifers. have a woody struc ture distinguishable only in entire sections of the stem. Goppert's example in dealing with the fossil woods has been followed, and they are di vided into genera] groups according to their re semblances to the wood of modern genera, as: Araucaroxylon (Dadoxylon), like wood of Nor folk Pine—Arauearia; Pissodendron; Cupress °Nylon, like wood of cypress; Pityoxylon. like wood of pine; Cedroxylon, like wood of cedar; Taxoxylon, like wood of yew. Of these, Ion is known only from the Tertiary; Cupress oxylon occurs only from the Chalk pine and cedar woods only from the Tertiary on ward. Arauearoxylon and Pissodendron are the only types of coniferous wood found in the Paleozoic formations. To Araucaroxylon prob ably belongs the wood of the Carboniferous pines and Dawson's species of Dadoxylon and Ormoxy Ion, from the Canadian Middle Devonian. But the wood of Cordaites has also the Arauearoxy Ion structure. The presence of true Conifers with this wood structure is, however. known from the Carboniferous. The stems of Protaxites Logani and Nematoxylon erassum, from the Lower Devonian of Canada and New Brunswick, which were described by Dawson as the oldest Conifer remains, are now considered to be remains of alge.
It has been determined that the conifers origi nated in the Arctic region, from whence they have spread over the globe. The pines (Pines) appeared first in the European early Cretaceous beds, where their cones are found, and they be came very abundant in the Tertiary. Thc firs are known from the Jurassic of Spitzbergen and Siberia, and the cedars date also from the Juras sic. The Arau•arians. to which belong also the (Bald Cypress) and the Sequoia: (Red wood), are thought to be represented by the gigantic Walehia of Permian age. The typical American bald cypress (Taxodium distiehum), which abounds in the swamps of Florida, occurs as the same 'species in the Miocene of Middle Europe. The \'oltzias, so common in the Trias sic sandstones of Germany, may also belong to the The cypress appears in the Triassic with a form extremely similar to a genus now found only in Afriea—Widdringtonhi. The cedar of Lebanon, the junipers. and others, make their earliest appearance in the Cretaceous of Green land. and are found in later fo•mations—Upper Cretaceous and Tertiary—of Middle Europe, an indication of the migration they made with the passing of geologic time. Salishurias are to-day represented by a single living type, the famous ginkgo (q.v.), which was first known in the cultivated state in the groves of Chinese tem ples. Ginkgo is the last descendant of a once great race, with ancestors that reach back as far as the Lower Carboniferous, and flourished. dur ing those periods, from the Triassie onward, in the northern parts of Europe, as Spitzbergen and Siberia, etc.
BIBLIOGRAPHY. Dawson, "The Fossil Plants Bibliography. Dawson, "The Fossil Plants of the Devonian and Upper Silurian Formations of Canada," Canadian Geoloyieal Survey (Otta wa, 1881, 1882) ; G5ppert, "Monographie der foseilen Coniferen," Yuturk undige Ferhandlinge run de Hollandsche Maatschappij der Wcten schoppcn, to ser. if, vol. vi. (Leyden, 1850) ; Zittel and Sehimper, Handbuch der Paltiontolouie, part ii. (Leipzig, 1879-85) ; same, French edition (Paris. Munich. and Leipzig, 1887) ; IL Graf zu Solms-Laubaeh, Fossil Bot any (Oxford, 1891). For illustrations, see ; PINES, etc.