256 



THE MICROSCOPE AND ITS REVELATIONS. 



HLAIE X 



DEVELOPMENT AND REPRODUCTION OF SPH-SJROPLEA ANNULINA (after Cohn). 



Fig. 1. Oospore, of a red color, having its outer membrane furnished with stellate prolonga- 

 tions. 



2, 3, 4. Successive stages of segmentation of the oospore. 



5. Fusiform flagellated zoospores set free by the rupture of the coats of the oospore. 



6, 7, 8. Successive stages of development of zoospore into a filament. 



9. Immature filament, showing at a the annulation of the endochrome produced by the regular 

 arrangement of vacuoles, and at b, the frothy appearance produced by the multiplication of 

 vacuoles. 



10. More advanced stage, showing at a the aggregation of the eudochrome into definite masses 

 which become star-shaped as seen at 6. 



11. The star-shaped masses of endochrome, a, draw themselves together again and become 

 ovoidal, as at 6 ; definite openings, c, show themselves in the cell-wall. 



12. Entrance of the antherozoids, d, through the openings, c, c. 



13. Formation of mature oospores within the filament. 



14. Contents of another filament, a, becoming converted into antherozoids, which move about 

 at b within their containing cell, and escape (as seen at d) through the opening c. 



15. Antherozoids swimming freely by means of two flagella. 



