3 12 
Woodburn . — Spermatogenesis in certain Hepaticae. 
Bibliography. 
Bolleter, Eugene, ’05 : Fegatella (L.) corda . Eine morphologisch-physiologische Mono- 
graphic. Beihefte zum Botanischen Centralblatt, xviii, 1905, pp. 348-50. 
Escoyez, Eud., ’07 : Blepharoplaste et centrosome dans le Marchantia polymorpha. La Cellule, 
xxiv, 2 e fas., 1907, pp. 247-56. 
Farmer, J. Bretland, ’95 : On Spore-formation and Nuclear Division in the Hepaticae. Ann. 
of Bot., ix, no. 35, Sept., 1895, pp. 469-523. 
Farmer, J. Bretland, and Reeves, Jesse, ’94 : On the Occurrence of Centrospheres in Pellia 
epiphylla , Nees. Ann. of Bot., viii, no. 30, June, 1894, pp. 219-24. 
Ikeno, S., ’03 : Die Spermatogenese von Marchantia polymorpha . Beihefte zum Botanischen 
Centralblatt, xv, 1903, pp. 65-88. 
Lewis, Charles E., ’06 : Embryology and Development of Riccia lutescens and Riccia cry sta Hina, 
Bot. Gaz., xli, 1906, pp. 109-38. 
Mottier, D. M., ’04 : The Development of the Spermatozoid in Chara. Ann. of Bot., xviii, 1904, 
pp. 245-54. 
’04 : Fecundation in Plants, 1904, p. 49. 
Schaffner, John H., ’08 : The Centrosomes of Marchantia polymorpha. The Ohio Naturalist, 
ix, no. i, Nov., 1908, pp. 363-88. 
Van Hook, J. M., ’00 : Notes on the Division of the Cell and Nucleus in Liverworts. Bot. Gaz., 
xxx, no. 6, Dec., 1900, pp. 394-9. 
EXPLANATION OF FIGURES IN PLATE XXV. 
Illustrating Mr. Woodburn’s paper on Spermatogenesis in Hepaticae. 
All figures were drawn with the aid of a camera lucida and with a Leitz apochromatic 2 mm. 
objective, 1*30 apert, with compensating ocular 18. Magnification 3000 at table level. 
Figs. 1-24. Porella. (Figs. 1-11 previous to the last division of the spermogenous tissue.) 
Fig. 1. Cytoplasm and nucleus in young antheridium. Nucleus in resting stage. 
Fig. 2. Nucleus in resting stage. 
Fig. 3. Cell in very young anteridium. Nucleus in early prophase. 
Figs. 4-6. Nuclei in various stages of prophase. 
Fig. 7. Cell showing number of chromosomes. 
Fig. 8. Metakinesis in young antheridium. 
Fig. 9. Anaphase. 
Fig. 10. Telophase. 
Fig. 11. Two cells shortly before entering upon last division. 
Fig. 12. A pair of sperm cells without the enclosing cell- wall. 
Fig. 13. A pair of sperm cells enclosed in cell-wall. Seen from the edge. 
Fig. 14. One sperm cell, seen from the side, showing blepharoplast primordium. 
Fig. 15. Sperm cell. Blepharoplast beginning to develop in length. 
Fig. 16. Blepharoplast slightly longer than in Fig. 15. 
Fig. 17. Blepharoplast half-way around the sperm cell. 
Fig. 18. A pair of developing sperms, showing blepharoplast. 
Figs. 19 and 20. Showing nucleus becoming more homogeneous than in Fig. 18. 
Fig. 21. Nucleus beginning to draw out along the blepharoplast. 
Figs. 22 and 23. Later stages of the sperm with the cilia partly developed. 
Fig. 24. Mature sperm escaped from the antheridium. 
