396 M. G. Sykes 
Stevens, W. C., Über Chromosomenteilung bei der Sporenbildung der Farne; 
Ber. d. d. bot. Ges. 1898. 
Strasburger, E., (I) Beduktionsteilung usw. Jena. 1900. 
(II) Über Beduktionsteilung. 1904. Sitzungsberichte der Königlich preußi- 
schen Akademie der Wissenschaften XVIII. 
(III) Typische und allotypische Kernteilung; P. J. 1906. p. 1. 
(IV) Die Ontogenie der Zelle seit 1875. Prog. rei. bot. I. 1. 1907. 
Wäger, H., The nucleolus and nuclear division in the root apex of Phaseolus. 
Ann. of Bot. 1904. p. 29. 
Explanation of Plates VIII & IX, 
The figures are drawn with the aid of a camera lucida from preparations 
examined with a Zeiss oil-immersion lens, and oculars 6 and 8. Except when 
otherwise mentioned sections were stained in haematoxylin by Heidenhain’s 
method. 
Plate VIII. 
Fig. 1. Somatic nudeus of Funkia ovata, from the epidermis of an anther, 
showing the double structure of the nuclear reticulum in early prophases. (X 
1150). 
Fig. 2. A similar nucleus from the wall of an anther; (stained Flemming). 
(X 1150'. 
Fig. 3. A nucleus from the wall of the ovary, showing a rather later pro- 
phase, in which the nuclear reticulum is double, while some of the granulär 
knots are paired and some single. (X 1150). 
Fig. 4. A nucleus from a petal, showing pairs of similar sized chromo- 
somes lying together. (Reichert Vis)- (X 1500). 
Figs. 5 & 6. Cells from root of Pisum, showing paired reticula and aggre- 
gations. (X 1350). 
Fig. 7. Anaphase of last archesporial nuclear division showing pairs of 
chromosomes. (X 1150). 
Figs. 8 & 9. Reconstruction of nucleus of pollen mother cell, showing 
very clearly paired reticulum. (X 1150). 
Fig. 10. Thicker section of resting stage of same, containing granulär reti- 
culum with 5 nucleoli. (X 1150). 
Fig. 11. Very early prophase of pollen mother nucleus, showing a yet 
unpaired reticulum with numerous granulär knots. (X 1150). 
Fig. 12. Early prophase of same, showing beginning of pairing in both 
reticulum and knots. (X 1150 . 
Fig. 13. Similar stage to the last but stained Flemming. (X 1150). 
Figs. 14 & 15. Similar stage to Fig. 12. here and in Figs. 15 & 16, the 
differentiation of the stain is such that the appearance is more granulär. (X 1150 . 
Fig. 16. More magnified portion of reticulum from same nucleus as Fig. 15 
but drawn at lower focus. 
Fig. 17. Similar stage to these, showing two large nucleoli and two small 
ones; darkly stained. (X 1150). 
Figs. 18 & 19. Slightly later stages, showing more definite and clearly 
paired aggregations in the reticulum, which is alse beginning to show signs of 
contraction. (X 1150). 
