. A handbook of cryptogamic botany. Cryptogams. 68 VASCULAR CRYPTOGAMS papilla divides first of all into a central cell surrounded by a single layer of peripheral cells. These last are barren, but contain chlorophyll; while the central cell divides still further, each derivative nearly cubical cell then producing a flat spirally-coiled antherozoid contained within a vesicle, or ' special parent-cell.' In no case is the number of anthero- zoids produced by a single antherid very considerable. The function of the peripheral cells appears to be to absorb water violently when the antherid is matur
. A handbook of cryptogamic botany. Cryptogams. 68 VASCULAR CRYPTOGAMS papilla divides first of all into a central cell surrounded by a single layer of peripheral cells. These last are barren, but contain chlorophyll; while the central cell divides still further, each derivative nearly cubical cell then producing a flat spirally-coiled antherozoid contained within a vesicle, or ' special parent-cell.' In no case is the number of anthero- zoids produced by a single antherid very considerable. The function of the peripheral cells appears to be to absorb water violently when the antherid is mature, in consequence of which they swell up considerably and rupture the central cells, thus causing the escape of the parent-cells of the antherozoids. From each of these is then discharged, by the bursting of its delicate cell-wall, an antherozoid consisting of a flat band of proto- plasm coiled spirally three or four times, and bearing at its anterior end a number of fine V- .."-l AV cilia (fig. 44). To its posterior end is frequently attached for a time a vesicle containing starch- grains, which is pro- bably the remains of the special parent- cell of the anthero- zoid. As in other Vascular Crypto- gams, the body of the antherozoid ap- pears to be formed from the nucleus of the mother-cell, the cilia from the cell-protoplasm. The archegones are produced on the under side of the cushion of the prothallium, but in much smaller numbers than the antherids. Like them, each archegone is derived from a single superficial cell, which at first bulges only slightly, and is first divided into three cells by two tangential walls. The lowermost of these three, or basal cell, divides further, and takes its share in the formation of the venter, or swollen part of the archegone, which is altogether imbedded in the prothallium. The outermost of the three cells develops into the neck-wall, or outer- most wall of the neck of the archegone, dividing at first into four cells, from which the f
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