. Studies in fossil botany . Paleobotany. STIGMARIA 247 direction, for it is on the inner edge of the secondary cortical zone that remains of the delicate phellogen can be traced. The tissue thus formed cannot have been of the nature of cork, for the outer tissue shows no sign of withering, and some of its cells had some- times undergone tangential division, as if starting a. Fig. 100.—Stigmariaficoidcs. Part of transverbe section, to show base of a rootlet, /a, periderm of main axis ; , outer cortex (including hypoderma) of main axis and of rootlet; , inner cortex, x, xylem of rootlet ;
. Studies in fossil botany . Paleobotany. STIGMARIA 247 direction, for it is on the inner edge of the secondary cortical zone that remains of the delicate phellogen can be traced. The tissue thus formed cannot have been of the nature of cork, for the outer tissue shows no sign of withering, and some of its cells had some- times undergone tangential division, as if starting a. Fig. 100.—Stigmariaficoidcs. Part of transverbe section, to show base of a rootlet, /a, periderm of main axis ; , outer cortex (including hypoderma) of main axis and of rootlet; , inner cortex, x, xylem of rootlet ; r>, tracheites passing out to rootlet. X about 15. (G. T. G.) new, more external phellogen. In many of the Car- boniferous plants the formation of secondary cortex played a much more important part than is usually the case in recent vegetation, and though we use the words " periderm " and " bark," it is certain that many of the structures thus indicated were very different in nature and function from the recent tissues which. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Scott, Dukinfield Henry, 1854-1934. London, A. and C. Black
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