142 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



the nucleus. Ten bivalent chromosomes may be counted in 

 diakinesis and in the equatorial plate stage. 



3. During the late telophase in the first division chromosome- 

 like bodies appear in the cytoplasm and on the spindle of pollen 

 mother-cells. The chromosome-like bodies resemble in general 

 the belated chromosomes in size, shape, and structure but on 

 closer examination they are found to be more like extranuclear 

 nucleoles. 



4. Similar bodies appear in the late telophase of the second 

 division. That these bodies are the same as those seen in the 

 first division is hardly possible, for no chromosome-like bodies 

 have been observed at any other stage than in the telophases of 

 the first and second divisions. 



5. The fate of the chromosome-like bodies is undetermined. 

 It is possible that they become dissolved in the cytoplasm after 

 the completion of each division. Perhaps these bodies are the 

 forerunners of abnormalities which bring about the disintegration 

 of the cell. Sterile pollen grains appear. 



5. Cell division of the pollen mother-cell is by bipartition or 

 successive division and quadripartition or simultaneous division. 

 In either case no cell plates have been observed. Cell division 

 may possibly take place by constriction as in the case of the 

 animal cells. The constriction furrows must be extremely narrow 

 in the species of Drosera, like those described in the slime moulds. 



Literature cited 

 1905. Allen, C. E. Nuclear division in the pollen mother-cells of 



Liliutn canadense. Ann. Bot. 19: 189-258. pi. 6-g. 

 1905. Andrews, J. M. Die Anatomie von Epigaea rcpens L. Beih. 



Bot. Ccntralhl. 19^: 314-320. pi. 6-8. 

 1901. Beer, R. The supernumerary pollen-grains of Fuchsia. Ann. 



Bot. 21: 305-307- 

 1912. Beer, R. Studies in spore dcvelopnu'nt. II. On the structure 



and division of the nuclei in the Compositae. Ann. Bot. 26: 



705 726. pi. 66, 6j. 

 1905. Berghs, J. La formation dcs chromosomes heterotjpiqucs dans 



la sporogenese v6getale. La Cellule 22: 141-160. pi. i, 2. 

 1907. Britton, N. L. Manual of the flora of llu' Northern United 



Slates and Canada. 

 1903. Cannon, W. A. Studies in plant hybrids. The spermatogenesis 



of hybrid cotton. Bull. Torrey (Muh 30: 133-196. pi. 7-10. 



