GROWTH OF CELLS.

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is limited or unlimited, according as it either ceases ata definite time, or continues as long as the plant lives.Apical growth is limited in all cells, growing at the apex,of many-celled plants, also in many axes of unicellularplants. It is unlimited in particular axes of unicellularplants, as, for instance, in the main axis of Caulerpa,Brgopsis, &c.

Apical growth is not found in all cells; it is wantingeven in the great majority of cells. I have observed itin unicellular Algae , as Caulerpa, Brgopsis, Vaucheria,Valonia, Codium, Halymeda, TJdotea ; in unicellular Fungi ,as Achlga, Bremia, Mucor, &c.; in the terminal cells ofmany Algae, Florideae, and Fungi , as, for instance, Con-ferva, Dasgcladus, Grifiithsia, Polgactis, &c.; in the rootsof many Algae , Florideae, and Fungi; in unicellularhairs, or the terminal cells of many-celled hairs, in thepollen-tube; lastly, in all cells growing out into a branch,as, for instance, in the cells forming the articulations ofmany Algae, Florideae, Fungi , and the organs consistingof series of cells in the higher plants, moreover in theepidermal cells of the higher and lower plants, &c.