Page:Microscopicial researchers - Theodor Schwann - English Translation - 1947.pdf/302

266 Fig. 10. Common partition-wall between two cells from fig. 9, under a higher magnifying power. “The stratiform depositions may be observed at b, and the porous canals produced by their local failure at a. I could distinctly enumerate from nine to twelve layers which had been deposited within fourteen days.

11. A sporule from Rhizina levigata Fries, with the cytoblast.

12, 13, 14. Different cytoblasts from the embryo-sac of Pimelea drupacea before the appearance of cells.

15. A young cell with its cytoblast, from the same. The latter in this instance presents the unusual number of three nucleoli.

16. A portion of the embryonal end of the pollen-tube projecting from the ovulum in Orchis Morio, within which, towards the upper part, cells have been already developed. At the lower part, the original pollen-tube may still be distinguished. The almost globular cytoblasts are, in this instance, distinctly enclosed in the cell-wall.

17. Embryonal end of the pollen-tube from Linum pallescens, together with an appended lobule of the embryo-sac (a). The process of the formation of cells is commencing. Above, a young cell with its cytoblast is already perceptible, beneath this several cell-nuclei are seen floating free.

18, 19, 20. Commencing germination in the sporules of Marchantia polymorpha. Compare the text, p. 248.

21. Portions of the pollen-tube which have become cellular, from Orchis latifolia, in the highest stage of development; the investment of the pollen-tube is no longer perceptible. The cytoblast is enclosed in the cell-wall, just as in fig. 16.

22 and 23. Two isolated cells from the terminal shoot (punctum vegetationis, Wolff) of Gasteria racemosa; 22 exhibits two free cytoblasts; 23, two newly-formed cells within the original cell.