Constituents of the Cell . 
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EXPLANATION OF FIGURES IN PLATE XX. 
Illustrating Dr. Humphrey’s paper on some Constituents of the Cell. 
All Figures are drawn from microtome-sections with the Abbe camera. 
Figs. 1-8. From sporangia of Osmunda regalis. 
Fig. i. Spore-mother-cell in the resting stage, before separation, x 1000. 
Figs. 2-6. Successive stages in the first division of a definitive spore-mother- 
cell. X 1 200. 
Fig. 7. Three young spores of a tetrad formed from a mother-cell, x 1200. 
Fig. 8. Division of a tapetal cell, showing dividing centrospheres. x 1000. 
Fig. 9. Osmunda cinnamomea. Young spore, after separation of tetrad, 
x 1 200. 
Figs. 10-12. From root-tip of Allium Cepa. 
Fig. 10. Cell in resting stage, x 1200. 
Fig. 11. Cell with dividing nucleus, at time of splitting of chromosomes; fixed 
with Hermann’s fluid, stained with fuchsin-iodine-green. x 1200. 
Fig. 12. Cell with dividing nucleus, at time of migration of daughter-chro- 
mosomes to poles ; fixed and stained by Hermann’s method for centrospheres, 
showing also many stained proteid granules, x 1200. 
