The structure & development of the mosses and ferns (Archegoniatae) . When ripe thewall cells are much compressed, but are always to be distinguished. Like the archegonia, the antheridia are sunk separately indeep cavities, which are formed in exactly the same the archegonia, however, the antheridium does notnearly reach to the top of the cavity, whose upper walls are inmany species very much extended into a tubular neck, whichprojects above the general level of the thallus, and throughwhich the spermatozoids are discharged. D 34 MOSSES AND FERNS CHAP. The Embryo After fertilisation
The structure & development of the mosses and ferns (Archegoniatae) . When ripe thewall cells are much compressed, but are always to be distinguished. Like the archegonia, the antheridia are sunk separately indeep cavities, which are formed in exactly the same the archegonia, however, the antheridium does notnearly reach to the top of the cavity, whose upper walls are inmany species very much extended into a tubular neck, whichprojects above the general level of the thallus, and throughwhich the spermatozoids are discharged. D 34 MOSSES AND FERNS CHAP. The Embryo After fertilisation is effected the egg develops at once acell-membrane and enlarges until it completely fills the cavityof the venter. The first division wall is more or less inclinedto the axis of the archegonium, but approaches usually thehorizontal. The lower of the two cells thus formed dividesfirst by a wall at right angles to the first formed, but this isfollowed in the upper half of the embryo by a similar division,so that the embryo is divided into nearly equal quadrants. In. m.
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Keywords: ., bookcentury1800, bookdecade1890, bookidstructuredev, bookyear1895
