. A handbook of cryptogamic botany. Cryptogams. CHARACEjE usurp the functions of the primary root. The upper of the two nodes is still at some distance from the apex of the prothallium, this apical portion above the upper node consisting of a few much shorter cells. From this upper node is. developed the new plant. It is divided by longitudinal septa into two inner and six or eight peripheral cells. The peripheral cells ultimately become rudimentary leaves, which do not, however, form a true whorl. In the midst of them appears a bud, or growing point, developed from one of the inner cells, fro
. A handbook of cryptogamic botany. Cryptogams. CHARACEjE usurp the functions of the primary root. The upper of the two nodes is still at some distance from the apex of the prothallium, this apical portion above the upper node consisting of a few much shorter cells. From this upper node is. developed the new plant. It is divided by longitudinal septa into two inner and six or eight peripheral cells. The peripheral cells ultimately become rudimentary leaves, which do not, however, form a true whorl. In the midst of them appears a bud, or growing point, developed from one of the inner cells, from which springs the new stem, in a direction nearly at right angles to that of the prothallium. At present the formation of the prothalhum has been observed only in the genus Chara. A remarkable instance of parthenogenesis has been recorded in Chara crinita (Wallr.). The species is dioecious, and male plants are extremely rare. On the female plants the oospheres develop into oosperms without apparently any possibility of their having been impregnated; and the spermo- carps thus formed germinate in the ordinary way. The Characese consist of only a compara- tively small number of species, but some of them very abundant, growing submerged in deep or in shallow, in stagnant or in running, or occasionally in brackish water. Several species are grown with great facility in fresh-water aquaria, where they multiply very rapidly. The presence of certain species may be detected by the fcetid odour of sulphuretted hydrogen given off when decaying. Phipson (Compt. Rend., Ixxxiv., 1879, pp. 316, 1078) attributes this odour to the presence of a ispecial substance which he calls characin. The typical genus Chara is distinguished by its power of extracting calcium carbonate frorii the water in which it grows, the whole plant becoming thus covered with a calcareous incrustation, which frequently renders it difficult to make out the structure. Hence the family has acquired the popular names of '
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