Note CW — Front matter (continued 3)

These are the same with the wood-cells elsewhere called discigerous tissue, and to which I have applied the terms uniporous and multiporous. The markings on the walls are caused by an unlined portion of the cell-wall placed in a disk or depression, and this often surrounded by an hexagonal rim of thickened wall; but in all cases these structures are less pronounced than in Dadoxylon, and less regular in the walls of the same cell, as well as in different layers of the tissues of the axis.