The sketches reproduced in fig. 44 have been drawn from specimens originally described by Cash and Hick in 1878[431]. The sections were cut from a calcareous nodule from the Halifax Coal-Measures containing fragments of various plants and among others a piece of cortical tissue, probably of a _Lepidodendron_ or _Stigmaria_. In a transverse section of this tissue one sees under a moderately high power that the cells have become partially separated from one another by the destruction of the middle lamellae (fig. 44 A). The cell-cavities and the spaces between the isolated cells contain numerous fine fungal hyphae, which here and there terminate in spherical swellings. One such swelling is shown under a low power in fig. 44 A, in the middle uppermost cell, and more highly magnified in fig. 44 B. In fig. C there are two such swellings (the larger one having a diameter of ·003 mm.) in contact, but the connection does not appear to be organic. The cell-walls of the infected tissue present a ragged and untidy appearance, and in places (_e.g._ fig. 44 D) the membrane has been pierced by some of the mycelial branches. [Illustration: FIG. 44. Cells with fungal hyphae. A. A piece of disorganised tissue, showing the separation of the cells. B. Part of A more highly magnified. C. A single cell containing two swollen hyphae. D. Partially destroyed cell-membranes pierced by fungal hyphae. (Drawn from sections in the Edinburgh Botanical Museum, originally described by Cash and Hick.)] This fungus bears a close resemblance to _Peronosporites antiquarius_, but it is impossible to determine its precise botanical position without further data. In Cash and Hick’s paper in which the above fungus is briefly dealt with, some small spore-like bodies are figured which the authors speak of as possibly a Myxomycetous fungus[432]. There is however no sound reason for such a supposition. As examples of Ascomycetous fungi found in silicified wood of Tertiary age, two species may be quoted from Felix. _Cladosporites bipartitus_ Felix[433], fig. 43, 3. The mycelium and conidia of this form were discovered in some Eocene silicified wood from Perekeschkul near Baku, on the shores of the Caspian. The conidia are elliptical or pyriform in shape and divided by a transverse septum into two cells. No traces were found of any special conidiophores. The mycelium consists of septate branched hyphae, rendered conspicuous by a brown colouration. Felix compares the fossil with the recent genera _Cephalothecium_ and _Cladosporium_. _Haplographites cateniger_ Felix[434], fig. 43, 4.