312 Allen— The Pollen- Mot her -Cells of Larix. 
EXPLANATION OF FIGURES IN PLATES 
XIV and XV. 
Illustrating Mr. Allen’s paper on the Pollen-Mother-Cells of Larix. 
All the figures were drawn with the aid of the camera lucida , and with a Zeiss 
apochromatic 2 mm. objective, 1-30 apert. ; all except Fig. 4, PI. XIV, with 
compens. oc. 8 ; Fig. 4, with compens. oc. 1 2. 
PLATE XIV. 
Fig. i. Cross-section of pollen-mother- cell of Larix europaea , DC., material 
gathered and fixed October 24 ; very early prophases, showing fibrous network 
in the cytoplasm. 
Fig. 2. Cell fixed March 15 following; an inter- fibrous material is new present. 
Fig. 3. Somewhat later stage, with rather thick cell-wall. 
Fig. 4. Small part of section of cell at same stage, cut tangentially to the 
nucleus; membrane not visible; the dark rounded bodies are chromatin, the 
lighter shaded masses linin ; fibres can be traced from the chromatin bodies into 
continuity with the cytoplasmic network. 
Fig. 5. A cell from the same section as Figs. 3 and 4 ; the cytoplasmic fibres 
have taken on a radial arrangement. 
Fig. 6. Radial stage, fibres running from nuclear membrane to plasma membrane. 
Fig. 7. Beginning of folding-over of fibres. 
Fig. 8. Fibres are gathering into felt just outside nucleus ; many extra-nuclear 
nucleoles present. 
Fig. 9. A cell somewhat shrunken, with the nuclear membrane plasmolysed and 
pushed inward. 
Figs. 10 and n. Later stages in the formation of the felt. 
PLATE XV. 
Fig. 12. The completed felt; nuclear membrane much folded, probably on the 
point of dissolution ; nucleole vacuolated. 
Fig. 13. The nuclear membrane has disappeared; nuclear cavity contains 
granular fibres of nuclear origin ; the outer fibres are being oriented to form the 
cones of the multipolar spindle. 
Figs. 14 and 15. Later stages in the formation of the multipolar spindle. In 
Fig. 15 the fibres are gathered into bundles which run from the poles to the 
chromosomes. 
Fig. 16. A multipolar figure ; the cell somewhat shrunken and plasmolysed ; 
a peripheral zone containing fibres and irregular * cyto-asters.’ 
Fig. 1 7. The fibres becoming straightened out and parallel ; a transition to the 
bipolar spindle. 
Fig. 18. A ‘ multipolar diarch ’ stage. 
Fig. 19. A completed spindle in the equatorial plate stage, showing polar 
radiations. 
Fig. 20. The diaster stage ; a few especially dense fibres or strands in the 
central spindle ; the polar radiations very numerous. 
