The microscope : and its application to vegetable anatomy and physiology / by Dr. Hermann Schacht ; edited by Frederick Currey, M. A.

Hermann Schacht

Date:: 1855

Credit: The microscope : and its application to vegetable anatomy and physiology / by Dr. Hermann Schacht ; edited by Frederick Currey, M. A. Source: Wellcome Collection.

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$]0l tlie hollow of the ovaiy. The middle part of the embryo-sac becomes filled ■with eudosperm at an early period; the other })arts of it never contain cells. The pollen-tube passes through the cell-less apex, which is connected with the front prolonga- tion (a), and when it reaches the endosperm, swells and forms the embryo; in this fiower many polleix-tubes are often found in the micropyle; (c) is the hilum of the o-vule. Fig. G1 represents the apex of the embiyo-sac of Lathi’sea squamaria prepared in a perfect and uninjured state, dra\vn from a perfectly fresh specimen : (a) is a pm-t of the front pro- longation (nee fig. 60). Two pollen-tubes have penetrated the embryo-sac, one has already swollen into a rudimentaxy embiyo within the endosperm, the other has peneti’ated but not deve- loped itself. Both pollen-tubes are seen ^xrotruding far out of the cell-less apex of the embiyo- sac. The outline of this apex on the ujiper side is seen cUstinctly. On the under side it appeal’s as a less defined line, which stands out clearly when the adjustment of the mici’oscope is altered. Both pollen-tubes are somewhat swollen in the pai’ts which project fx’om the embi-yo-sac; they pass otf by degi’ees into a thin ragged end. The part of the pollen- tube which lies in the mici’opyle is generally so much softened that it is not possible to detach, a lai’ge piece of it; the pollen- tube which has peneti’ated the embryo-sac is frequently broken off at the end which projects from the embryo-sac. Two pol- len tubes ai’e often foimd in the embryo-sac of Lathrsea, but one only developes an embiyo. Fig. 62 represents a preparation quite as perfect as that shown$