184 THE BOTANICAL MAGAZINE. Voi. xxxiii. n ,. 393. 



EXPLANATION OF PLATE IL 



Fig. ]i Z )Ospores as seen on 27 D<^ceraber, 1915. X 650. 



Fig. 2. Zoospores as seen on 6 Ai)ril, 1918. X 565. 



Fig. 3. Zoospores resting. X 850. 



Fig. 4. Beginning of the germination. The eye-spot, cliroinoplasl and nucleus are 



single in each sporeling. X 850. 

 Fig. 5. Sporelings of two-celled stage. The* eye-spots are no more to be seen. 



X 850. 

 Fig. 6. Sporeling of four-celled stage. X 565, 

 Fig. 7. Sporeling of five-celled .stage. X 565. 

 Fig. 8. Sporeling with the hair from the initial coll. X 565. 

 Fig. 9. Sporeling witli two antlieridia and three oogonia ; one antheridiuni is 



emptied, and the other not yet fully ripened as the waste of the chromo- 



plast is still within it. X 565. 

 Fig. 10. Sporeling with four immature oogonia and one ripened antheridium; the 



waste of the chromoplast is now excluded from tlie sporangial sack. The 



hair is generated at an abnurraal position on the initial cell. X 565. 

 Fig. 11. Part of a sporeling filament with a series of oogonia; a, hall-formed 



oospore septated from the mother-cell: b, fully formed oospore ready to 



separate from the mother-cell. X 850. 

 Fig 12. Pari of two filaments to show mature antheridia. In a, two antheridia in 



normal form, one emptied and the other ready to discharge the contents: 



in b, the emptied antheridium is in normal shape and size, but the others 



somewhat abnormal in tiiese respects. X 850. 

 Fig. l.S. AVithered filaments and young and germin.iting oospores. X 565. 

 Fig. 14. Germination of oospores up to a thiee-celled stage. X 565. 



