146 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



Explanation of plates 



All the figures were drawn with the aid of a camera lucida from preparations stained 

 with Flemming's triple stain. Leitz 1/16 objective and ocular 4 were used in making 

 the outlines but ocular 3 with the draw tube extended 15.2 cm. was used in drawing the 

 cytoplasmic and nuclear details. 



Plate 16 

 Drosera intermedia Hayne 



Fig. I. Resting stage of an immature pollen mother-cell, X 2,666. 



Fig. 2, Polar view of an equatorial plate stage of the premeiotic division of a 

 pollen mother-cell, X 2,700. 



Fig. 3. Late anaphase of a somatic division, X 2,700. 



Fig. 4. Similar stage, showing the chromosomes very distinctly in young pollen 

 mother-cell, X 2,700. 



Fig. 5. Beginning of a cell plate in the division of a vegetative cell, X 2,700. 



Fig. 6. A slightly older stage, X 2,700. 



Fig. 7. Cell plate in the premeiotic division of a pollen mother-cell, X 2,700. 



Fig. 8. Completion of the cell plate in the division of a vegetative cell, X 2,700 



Fig. 9. Diakinesis, showing bipartite and quadripartite chromosomes, X 2,666. 



Fig. 10. Equatorial plate stage of the heterotypic division of a pollen mother- 

 cell, X 2,666. 



Fig. II. Polar view of an equatorial plate stage in the heterotypic division, X 2,666. 



Fig. 12. Anaphase stage of a pollen mother-cell in the heterotypic division, X 2,666- 



Fig. 13. Interkine.sis, showing the chromosome-like bodies scattered in the cyto" 

 plasm and on the spindle fibers, X 2,666. 



Fig. 14. Early anaphase stage of the homoeotypic division, X 2,666. 



Plate 17 

 Drosera rotundifolia (magnification, 2,666 diameters) 

 Resting nucleus of a pollen mother-cell, showing paired prochromosomes. 

 Leptoneme spireme, showing a single beaded structure. 

 Early stage in synapsis. 



Same as Fig. 17, showing a somewhat later stage. 

 Early stage in diakinesis. 

 Equatorial plate stage of the first division. 

 Fig. 21. Polar view of an early anaphase stage. 

 Fig. 22. Late anaphase stage of the first division. 



Fig. 23. Interkinesis, showing chromosome-like bodies in the cytoplasm and on 

 the spindle fibers. 



Fig. 24. Reconstruction stage after the homoeotypic division, showing chromosome" 

 like bodies on the spindle fibers. 



Drosera filiformis 

 Fig. 25. Reconstruction stages after the homoeotypic division, showing chromo- 

 some-like bodies. 



Plate 18 

 Drosera filiformis 

 Fig. 26. Leptoneme spireme, showing the double thread-like chromatin bands, 

 X,2,I25. 



Fig. 27. Leptoneme spireme, showing the beaded structure of the chromatin bands, 

 X 2,125. 



