226 Cytologn and Genetics of the Genus Fuchsia 



EXPLANATION OF PLATES. 



For Figs. 18, 25, 26, 27, and 28, an one-eighth inch objective and No. 2 compensating 

 eye-piece were used; for all other Figs, a Zeiss 2 mm. lens of 1-40 N.A. and an 18 com- 

 pensating eye-piece were employed. 



PLATE XXII. 



Figs. 1 — 13. Fuchsia hybrid. Stages of first meiotic division in pollen-mother-cells. 

 X 2700. 



Figs. 14 and 17. Fuchsia hybrid. Stages of second meiotic division in pollen-mother- 

 cells. X 2700. 



PLATE XXIII. 



Figs. 15 and 16. Fuchsia hybrid. Stages of second meiotic division in pollen-mother- 

 cells. X 2700. 



Fig. 18. Fuchsia hybrid. Ten young pollen grains all derived from one pollen-mother-cell. 



Fig. 19. Fuchsia hybrid. Supernumerary cells all derived from one pollen-mother-cell. 

 X 2700. 



Figs. 20 and 21. Fuchsia rjlobosa. Telophase of first meiotic division of pollen-mother- 

 cells. X 2700. 



Fig. 22. Fuchsia ylobosa. Second meiotic division ; early anaphase, x 2700. 



Figs. 23 and 24. Fuchsia corallina. First meiotic division of pollen-mother-cells, x 2700. 



Fig. 25. Geranium ibericum. Eight young pollen grains all derived from one pollen- 

 mother-cell. 



Fig. 26. Geranium ibericum. Binucleate and tetranucleate protoplast escaping from in- 

 complete wall on slight pressure. 



Fig. 27. Fuchsia hybrid. Pollen grain with only a single interstitial body. 



Fig. 28. Trayopoyon pratensis. Nine pollen grains all derived from one pollen-mother-cell 

 as a result of low temperature. 



PLATE XXIV. 



Fuchsia virgata x F. fulgens. Two plants (3 R and 8 T) of Fj. 



LITERATURE CITED. 



1. Beer, R. "The Supernumerary Pollen -grains of Fuchsia." Ann. But. Yol. xxi. 



p. 305, 1907. 



2. Blackburn, K. B. and Harrison, J. W. "The Status of the British Rose 



Forms as determined by their cytological Behaviour." A7in. Bot. Vol. xxxv. 

 p. 159, 1921. 

 .3. Bonnet, J. "Recherches sur revolution des cellules-noun-icieres du pollen chez 

 les Angiospermes." Archiv f. Zellforschimg, Bd. vii. 1912. 



4. DoRSEY, ]\I. J. " Pollen Development in the Grape with special reference to 



Sterility." University of Minnesota Agric. Expt. Stat. Bull. 144, 1914. 



5. FARMEit, J. B. and Digby, L. " On the cytological Features exhibited by certain 



varietal and hybrid Ferns." Ann. Bot. Vol. xxiv. p. 200, 1910. 



6. Gard, M. "Etudes anatomiques sur les Vignes et leurs hybrides artificiels." 



Act. Soc. Linn. Bordeaux., Ser. 6, Tom. viii. pp. 185 — 319, 1903. 



7. Gates, R. R. and Goodspeed, T. H. " Pollen Sterility in relation to Crossing." 



Science, N. S. Vol. xliii. pp. 859—861, 1916. 



8. Hildebrand, Fr. " Ueber einige Pflanzenbastardierungen." Jen. Zeitsch. /. 



Xaturwiss. Bd. xxiii. pp. 413- 548, 1889. 



