Identifier: sexualreproducti00harp (find matches)
Title: Sexual reproduction and the organization of the nucleus in certain mildews
Year: 1905 (1900s)
Authors: Harper, R.A
Subjects: Mildew
Publisher: Washington, Carnegie Inst.
Contributing Library: Robarts - University of Toronto
Digitizing Sponsor: University of Toronto

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conspicuous. Fig. 33.—^Just before nuclear fusion in ascus. Lower nucleus lies above andpartially overlapping the other. Fig. 34.—Section of ascus with slice of one nucleus showing three chromatinstrands and sections of others. Fig. 35.—Early stage in fusion of nuclei; central body of upper nucleus haspushed ahead on the membrane of the lower nucleus, its chromatin system drawnout in long cone. Fig. 36.—Stage of fusion. Central bodies and chromatin of two nuclei side byside, but independent; nucleoli already combined in one. Fig. 37.—Chromatin systems overlapping, but distinct. Nucleoli in contact Fig. 38.—Stage just before the central bodies combine; nucleoli in this casestill separate. Fig. 39.—The central bodies are joined side by side. Chromatin ssrstems com-bining. Fig. 40.—Central bodies and chromatin systems completely combined. Nucleolistill separate. Fig. 41.—Shows entire ascus; stage about the same as in fig. 40. Fig. 42.—Fusion of nuclei complete. <\^
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98 EXPLANATION OF FIGURES IX PLATES. Plate TV.—Phyllactinia cxir\t.ea. Fig. 43.—Early stage in synapsis. Fig. 44.—Synapsis; ends of chromatin strands protruding from contracted mass.Fig. 45.—Late sjTiapsis stage stained to specially differentiate the central body.Fig. 46.—Loosening up of chromatin after synapsis.Fig. 47.—Early spirem stage. Fig. 48.—Culmination of spirem stage; eight distinct chromatin strands corre-sponding to eight chromosomes of later stages.Fig. 49.—Same stage; strands spreading from center without forming cone.Fig. 50.—^Young penicillate cell. Three nuclei showing central bodies.Fig. si.—Full-grown penicillate cell. Fig. 52.—Transverse section of ascus, showing prophase in formation of spindle.Fig. 53.—Primary nucleus of ascus; equatorial-plate stage, eight chromosomes.

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