. The Characeae of America. root-node, consisting of several Fig. nodal eel's, from which several rootlets arise. Fig. 6 represents a section through the primary node—"r," the rootlets; "p,"the protonema; "pr. r," the primary root-node; "sm.," spore membrane. Fig. 7. Front view of node of Ch. coronata; letters as above; "sh.," shell of nucleus. These and all subsequent roots form, by acropetal division, a series of much elongated cells with swollen joints (nodes); these nodes are like two feet, united by their soles in opposite directions,
. The Characeae of America. root-node, consisting of several Fig. nodal eel's, from which several rootlets arise. Fig. 6 represents a section through the primary node—"r," the rootlets; "p,"the protonema; "pr. r," the primary root-node; "sm.," spore membrane. Fig. 7. Front view of node of Ch. coronata; letters as above; "sh.," shell of nucleus. These and all subsequent roots form, by acropetal division, a series of much elongated cells with swollen joints (nodes); these nodes are like two feet, united by their soles in opposite directions, and from the dorsum of the foot, directed toward the point of the root, single rootlets, or bunches of rootlets, arise by a superficial proliferation of cells. Fig. 8 represents a root- node of Nitella megacarpa, Allen, with two young rootlets (drawn from nature, T. F. A.) The other cell, arising by the divis- ion of the primary nodal cell, grows in an ascending direction, opposite to that of the primary root, and elongates into a tube which divides by horizontal fis- sation into three to seven cells; these become filled Math chlorophyll and assume the appearance of a leaf of a Charad. This ceases to elongate and is now the protonema (pro-embryo), from which the perfect plant arises in the follow- ing manner : The lowest cell of the pro- tonema undergoes -divis- ion near its upper part, by a septum which inter-. 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 Allen, Timothy Field, 1837-1902. New York : [s. n. ]
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