266 EXPLANATION OF THE PLATES. 
Fig. 10. Common partition-wall between two cells from fig. 9, 
under a higher magnifying power. “The stratiform 
depositions may be observed at J, 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, 18, 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 pal- 
lescens, 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 cel- 
lular, 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. 
