. The cytoplasm of the plant cell. Plant cells and tissues; Protoplasm. GuilHermond - Atkinson . —44— Cytoplasm the vegetative structure, varying according to the cells in which they are found. They are irregular, or angular, disc-shaped bodies or twisted ribbons. Moreover, chlorophyll is lacking in the rhizoids and sexual organs. In the Charophytes there is little chlorophyll in the apical cell and small ovoid chloroplasts are often found there containing a large number of starch grains. In this group also, chlorophyll is lacking in the egg and in the antherozoids. In the bryophytes, the chlo
. The cytoplasm of the plant cell. Plant cells and tissues; Protoplasm. GuilHermond - Atkinson . —44— Cytoplasm the vegetative structure, varying according to the cells in which they are found. They are irregular, or angular, disc-shaped bodies or twisted ribbons. Moreover, chlorophyll is lacking in the rhizoids and sexual organs. In the Charophytes there is little chlorophyll in the apical cell and small ovoid chloroplasts are often found there containing a large number of starch grains. In this group also, chlorophyll is lacking in the egg and in the antherozoids. In the bryophytes, the chloroplasts are numerous and similar to those of the phanerogams. Yet in Anthoceros there is only one crescent-shaped chloroplast per cell, situated near the nucleus. It is transmitted by division from cell to cell. It is therefore clearly proved by the study of algae such as the Conjugatae where the chloroplasts are present in all cells, are voluminous, and number only one or two per cell, that these organ- elles are transmitted from cell to cell beginning with the egg. However, their behavior during fertilization is not yet very clear, for it is very difficult to observe them in the zygote. In the Desmidiales (Closterium and Cosmarium), in which the cells contain two chloroplasts, Klebahn has stated that they fuse two by two in the zygote. Nevertheless, it is difficult to accept this supposed fusion, for it has never been observed in other cases. In another Desmid, Hyalotheca dissiliens, in which the cells have only one chloroplast, it seems well established by the recent work of PoTTHOFF that one of the two chloroplasts, de- — A Dividin ^ived from each of the gametes brought to- chioropiasts in'leaT cells gether in the zygote, begins to degenerate and of Eiodea canadensis. B. (jigappears vcry rapidly. This is likewise re- Final stages in division *^^ ./!;'»' x rz J? of one chloroplast. ported for other Conjugatae. In Zygnema, tor example, where there are two chloroplasts
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