in the structure of their wood, whereby the smallest fragment may be identified.
Recent microscopic examinations of fossil woods have led to the recognition of an internal structure, resembling that of existing Coniferæ, in the trunks of large trees, both in the Carboniferous series,[1] and throughout the Secondary formations;[2] and M. Ad. Brongniart has enumerated twenty species of fossil Coniferæ in strata of the Tertiary series. Many of these last approach more closely to existing Genera than those in the Secondary strata, and some are referable to them.
It has been further shown by Nicol, (Edin. New. Phil.
Journal, January, 1834) that some of the most ancient fossil
Coniferæ may be referred to the existing genus Pinus, and
others to that of Araucaria; the latter of these comprehends
some of the tallest among living trees, (See Pl. l, Fig.
>br />The recognition of these peculiar characters in the structure of the stem, is especially important to the Geological Botanist, because the stems of plants are often the only parts which are found preserved in a fossil state.
- ↑ The occurrence of large coniferous trees in strata of the great Coal formation, was first announced in Mr. Witham's Fossil Vegetables, 1831. It was here stated that the higher and more complex organizations of Coniferæ exist in the Coal fields of Edinburgh and Newcastle, in strata which till lately have been supposed to contain only the simpler, forms of vegetable structure.
- ↑ In the lower region of the Secondary strata, M. Ad. Brongniart has enumerated, among the fossil plants of the New red sandstone of the Vosges, four species of Voltzia, a new genus of Coniferæ, having near allinities to the Araucaria and Cunninghamia. Branches, leaves, and cones of this genus are most abundant at Sultz les Bains, near Strasburgh.
Mr. Witham reckons eight species of Coniferæ among the fossil woods of the Lias; and five species, of which four are allied to the existing genus Thuia, occur in the Oolite formation of Stonesfield. (See Ad. Brongniart's Prod. p. 200.) For figures of Cones from the Lias and Greensand near Lyme Regis, and the Inferior oolite of Northamptonshire, see Lindley and Hutton's Fossil Flora, Plates 89, 135, 137.
Dr. Fitton has described and figured two very beautiful and perfect cones, one from Purbeck ? and one from the Hastings sand. Geol. Trans. 2d. Series, Vol. iv. Pl. 22; Figs. 9, 10, p. 181 and 230.
