230 
GEORGE S. BRYAN 
6. Occasionally the egg may degenerate, while the protoplast of the 
ventral canal cell remains functional. 
7. Further work is needed to determine how general this condition is 
in other species of Sphagnum, and to follow the history of the fusion nucleus. 
Department of Botany, 
University of Wisconsin 
LITERATURE CITED 
1. Bryan, G. S. The archegonium of Sphagnum suhsecundum. Bot. Gaz. 59: 40-56. 
Pis. 4-7. 1915. 
2. Gayet, L. A. Recherches sur le developpement de I'archegone chez les Muscinees. 
Ann. Sci. Nat. VIII. Bot. 3: 161-258. Pis. 7-13. 1897. 
3. Hofmeister, W. Vergleichende Untersuchungen der Keimung, Entfaltung und Frucht- 
bildung hoherer Kryptogamen. Leipzig, 1 851. 
4. van Leeuwen-Reijnvaan, J. and W. Docters. liber eine zweifache Reduktion bei der 
Bildung der Geschlechtszellen und darauf folgende Befruchtung mittels zwei Sper- 
matozoiden und iiber die Individualitat der Chromosomen bei einigen Polytrichum- 
Arten. Rec. Trav. Bot. Neerl. 4: 177-220. Pis. 5-6. 1908. 
5. Melin, E. tlber das Archegonium von Sphagnum squarrosum Pers. Svensk. Bot. 
Tidskr. 10: 289-311. 1916. 
6. Roze, E. De la fecondation chez les Cryptogames superieures, et en particulier 
chez les Sphaignes. Bull. Soc. Bot. France 19: 91-102. PI. i, 1872. 
7. Schimper, W. P. Versuch einer Entwickelungsgeschichte der Torfmoose. Stuttgart, 
1858. 
8. Waidner, M. Die Entwicklung der Sporogone von Andreaea und Sphagnum. Pp. 
25. Pis. 1-4. Leipzig, 1887. 
9. Walker, N. On abnormal cell-fusion in the archegonium; and on spermatogenesis in 
Polytrichum. Ann. of Bot. 27: 1 15-132. Pis. 13-14. 1913. 
EXPLANATION OF PLATES 
All figures were drawn at table level with the aid of a camera lucida, using Spencer 
ocular 10 X and 1.5 mm. oil immersion objective. Being reduced one half in reproduction, 
they show a magnification of approximately 1000 X. 
Plate XIV 
Fig. I. Ventral cell of an archegonium having eight neck canal cells. Peculiarly 
shaped plastids in the cytoplasm. 
Fig. 2. Ventral canal cell and egg still separated by a wall, showing the difference in 
size of the two nuclei. Contraction of the protoplasts is probably due in large part to 
plasmolysis. 
Fig. 3. Wall has disintegrated, protoplasts have rounded off and are lying in contact 
in the venter. Nuclei and protoplasts practically identical in size. 
Fig. 4. The two protoplasts in closer contact but outline of each distinct. Disin- 
tegrated material from canal row in contact with upper protoplast. 
Fig. 5. Protoplasts have completely fused. Nuclei in contact, but each distinct. 
Plate XV 
Fig. 6. The fusion of protoplasts and nuclei completed. Mucilaginous matter be- 
ginning to appear about the protoplast. 
Fig. 7. The disintegration of the ventral canal cell. Only a blurred mass remains. 
Fig. 8. The rounded protoplasts. That of the ventral canal cell is smaller and has a 
smaller nucleus than the egg. 
Fig. 9. Protoplast of the ventral canal cell is larger and has a larger nucleus than the 
egg. 
