The structure & development of the mosses and ferns (Archegoniatae) . llulose membrane, whichprevents the entrance of the other spermatozoids. The eggnucleus moves towards the receptive spot at the time of 348 MOSSES AND FERNS CHAP. fertilisation, where the spermatozoid may be seen but littlealtered in form. It almost at once comes into contact withthe female nucleus, and the two then move toward the centreof the ovum. Here the spermatozoid gradually loses its coiledform and contracts until it becomes oblong, and in closecontact with the egg nucleus, in some cases looking as if itwere actually
The structure & development of the mosses and ferns (Archegoniatae) . llulose membrane, whichprevents the entrance of the other spermatozoids. The eggnucleus moves towards the receptive spot at the time of 348 MOSSES AND FERNS CHAP. fertilisation, where the spermatozoid may be seen but littlealtered in form. It almost at once comes into contact withthe female nucleus, and the two then move toward the centreof the ovum. Here the spermatozoid gradually loses its coiledform and contracts until it becomes oblong, and in closecontact with the egg nucleus, in some cases looking as if itwere actually within it. The process is a slow one, and in onecase twenty-four hours after the entrance of the spermatozoidthe two nuclei were still recognisable. Finally they arecompletely fused, and a single nucleus, with usually, perhapsalways, two nucleoli is seen. No sign of a separation of thechromosomes of the copulating nuclei was observed. The Embryo The first division of the ovum is the same with respect tothe archegonium as in Onoclea, the basal wall is parallel.
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Keywords: ., bookcentury1800, bookdecade1890, bookidstructuredev, bookyear1895
