PLATE 57 



APHANOMYCEi PARASITIC^ n. Sp. 



Fig. I. Threads of the parasite growing out through the walls of an Ac':!ya hypha after 



completely filling it. X 122. 

 Fig. 2. Oogonia; most within, one outside the Aclilya threads. X 122. 

 Fig. 3. Sporangia; formed outside the Achlya. X 278. 



Fig. 4. Young threads of the parasite growing through an Achlya thread. X 1012. 

 Fig. 5. Hyphae of the parasite attacking an actively growing thread of .-l("/!/va. A vacuole 



appears just in front of the growing tip of a parasite thread which has been 



turned back thereby. X 1012. 

 Fig. 6. A young oogonium and antheridium. X 810. 

 Fig. 7. Surface view of an r ogonium inside an Achlya thread, showing large, sharp spines. 



X 1012. 

 Fig. 8. Oogonia and antheridia within an Achlya oogonium. X 503. 

 Fig. 9. Oogonia and antheridia within an Achlya hypha. X 810. 

 Fig. 10. Oogonium with ripe egg, showing eccentric structure; antheridium attached. 



X 1012. 

 Fig. II. Oogonium with ripe egg shown at an angle which obscures the eccentric structure: 



antheridium attached. X 1012. 

 Fig. 12. Oogonia and antheridia. X 503. 

 Fig. 13. Oogonia and antheridia. X 1 01 2. 



All oogonia shown, e.xcept one in Fig. 12, were formed inside the host. 



