Pythium de Baryanum . 
667 
EXPLANATION OF FIGURES IN PLATE XXXVL 
Illustrating Mr. Miyake’s paper on the Fertilization of Pythium . 
All figures were sketched with the aid of the camera lucida, using Bausch and 
Lomb’s r Vin. oil immersion objective with ocular 1 (x 1300), except Fig. 28, 
which was drawn with Zeiss’ apochromatic 1-5 mm., 1.30 apert., homog. immer- 
<*sion objective, compensation ocular 12 (x 2700). 
Fig. 1. Portions of mycelium showing several nuclei. 
Fig. 2. The formation of an intercalary oogonium. 
Fig. 3. The formation of a terminal oogonium. 
Fig. 4. Intercalary oogonium with an antheridium attached in one side. 
Figs. 5-6. Terminal oogonia. 
Fig. 7. Young oogonia with a stalk-antheridium. 
Figs. 8-9. Young oogonia with branch-antheridia. 
Fig. 10. An oogonium with two antheridia. - 
Fig. 11. An oogonium with a branch-antheridium. 
Fig. 12. An oogonium with the nuclei dividing near the periphery. 
Fig. 13. An oogonium with a stalk-antheridium, the nuclei of both are dividing 
or just about to divide. 
Fig. 14. An oogonium with a branch-antheridium, the nuclei of both are just 
dividing. 
Fig. 15. An antheridium, showing a dividing nucleus. Only a part of oogonium 
is shown. 
Fig. 16. An oogonium with a branch-antheridium, the stage a little later than 
Fig. 14. 
Fig. 17. The contents of an oogonium as just differentiating into the ooplasm 
and periplasm. 
Fig. 18. Later stage: the oosphere is formed, showing the degenerating nuclei 
in the periplasm. The antheridium with one functional nucleus and several 
degenerating nuclei is shown in one side. 
Fig. 19. The antheridium discharging the contents : the male nucleus just 
entered the oosphere. 
Fig. 20. The male nucleus is approaching the female nucleus. The thin wall is 
formed around the oosphere. 
Fig. 21. Two sexual nuclei are just in contact. 
Fig. 22. A stage same as Fig. 20, with a stalk-antheridium. 
Figs. 23-24. Young oospores each with a single nucleus, and the exospore are 
nearly complete. 
Fig. 25. An oospore with the endospore about half-way thickened. 
Fig. 26. An oospore in a stage older than Fig. 25. 
Fig. 27. Nearly ripe oospore with oogonial wall, emptied antheridium still 
attached. 
Fig. 28. Several karyokinetic figures, a, b, d, e in oogonium, c in antheridium. 
