Spindle in Vegetable Cells of Higher Plants 



459 



Fig. 3. The spindle anlage consists of two cone-shaped caps on opposite sides of 

 the nucleus. The fibers converge into one pole at the lower end, but form two or more 

 at the upper end. 



Fig. 4. Similar spindle anlage, but both poles broadly truncate. 



Fig. 5. Spindle anlage similar to Fig. 4. The chromatin spirem which winds regu- 

 larly in the nucleus is drawn as seen from the surface. 



Fig. 6. The spindle anlage consists of a cylindrical complex of fibers in which the 

 nucleus lies. The nuclear membrane has begun to disappear. 



Fig. 7. The nuclear membrane has disappeared. The chromosomes are being 

 oriented in the nuclear plate ; the spindle poles are very truncate. 



Fig. 8. Similar to Fig. 7. The mantle fibers are more pronounced. 



Fig. 9. Chromatin more crowded in the center of the spindle-fiber complex. 

 Segmentation of spirem has probably taken place. 



Fig. 10. Chromatin spirem in all probability unsegmented ; it is much con- 

 tracted ; a large nucleolus is still present. The chromatin in Figs. 9 and 10 seem to in- 

 dicate that these divisions were not preceded by a period of complete rest. 



Fig. 11. Spindle monoaxial but multipolar; chromosomes not quite arranged in 

 the equatorial plate. 



Fig. 12. Chromosomes arranged in the nuclear plate ; the spindle is still multi- 

 polar in this case, but in this stage it is usually strictly bipolar. This is a mature 

 spindle. . 



Fig. 13. Karyokinetic figure in an aphase. 



Fig. 14. Chromosomes have arrived at the poles ; the cell plate is being laid down 

 in the connecting fibers. 



Literature 



Guignard, L., '98. Les centres cintetiques chez les vegetaux. Ann. 



des sci. Nat. Bot. III., 5: 177. 1898. 

 Hof, A. C, 98. Histologische Studien an Vegetationspunkten. Bo- 



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Mottier, D. M., '97. Beitrage zur Kenntniss der Kerntheilung in den 

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 fiir wiss. Bot. 30: 169-200. 1897. 



'97. Ueber das Verhalten der Kerne bei der Entwickelung 



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fiir wiss. Bot. 30 : 



1897. 



Nemec, Bohumil, '99. Ueber die Karyokinetische Kerntheilung in 



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1899. 

 Osterhaut, W. J. V., '97. Ueber Entstehung der karyokinetisch 



Spindel bei Equisetum. Jahrb. fur wiss. Bot. 30: 160-167. 



1897. 

 Shaffner, J. H. '98. Karyokinesis in the Root Tips of Allium cepa. 



Bot. Gaz. 26 : 225 



1898. 



