﻿1 903 ] OOGENESIS IN SAPROLEGNIA 349 



Fig. 17. Young ^^^, nucleus larger than in Fig. 16. 

 Fig. 18. Young ^^^\ coenocentrum without radiations. 



i' 



Fig. 19. Egg, older than in Figs. 17 and 18; nucleus larger. 

 f Fig. 20. Egg with nucleus extended toward coenocentrum, which has 



» almost disappeared. 



Fig. 21, Mature ^^%\ large nucleus; coenocentrum disappeared. 



Fig. 22. Young binucleate egg, the two small nuclei close to the smaller 



t 



coenocentrum. 



Fig. 23. Young egg with two coenocentra, each accompanied by a nucleus. 

 Fig. 24. An exceptionally large binucleate egg with prominent coeno- 

 centrum. 



Fig. 25. Egg with two nuclei lying over one another, both extended 

 toward the coenocentrum. 



Fig. 26. Binucleate ^^^^ with the nuclei at a distance from one another. 



Fig. 27. Binucleate egg with the nuclei close together. 



Fig. 28. Trinucleate ^%g, the three nuclei lying close together. 



Fig. 29. Trinucleate egg, the three nuclei at a distance from one another. 



(Figs. 30-35 illustrate sporogenesis.) 

 j Fig. 30. End of sporangium showing development of central vacuole. 



Fig. 31. Portion of cross section of sporangium, central vacuole well 

 I developed. 



Fig. 32. Early stage of segmentation; cleavage furrows running from 

 central vacuole to periphery. 



FiG. 33. After cleavage furrows have reached periphery, spore origins 

 forming. 



Fig. 34. Spore origins older than in Fig. 33. 

 Fig. 35. Zoospores in sporangium. 



\ 



