l66 Transactions British Mycological Society. 



failure to secure germination of the sclerotia, sclerotial plates 

 have not been obtained in culture from a single sclerotium. 



3. At a later date, a fungus agreeing in morphological and 

 cultural characters was encountered on tea and Bixa Orellana. 



4. What is considered the same fungus was afterwards dis- 

 covered on Coffea robusta and Casuarina equisetifolia, but has 

 not yet been isolated from either. 



5. To date, the inoculation experiments attempted have dealt 

 only with the important question of the susceptibility or im- 

 munity of Coffea arahica to the Rhizoctonia. The results have 

 been entirely negative. 



The writer wishes to express his thanks for help in the 

 systematic portion of this paper to Miss Wakefield of the Kew 

 Herbarium and to Mr E. W. Mason of the Imperial Bureau of 

 Mycology, and his indebtedness to the Director of the Bureau 

 for laboratory facilities. 



EXPLANATION OF PLATES V AND VI 

 Figs. 



1-2. Hyphae in wood and cortex of a Grevillea root, x 250. 



3. Hyphae in a medullary ray cell, x 250. 



4. Portion of a sclerotial plate in Grevillea root, x 150. 



5. Hyphae of a sclerotial plate, x 400. 



6. First stage in sclerotial-formation in G>'ez;i7/ea tissues. X250. 



7. Hyphae and part of a mature sclerotium in wood of a Grevillea root. 



X250. 



8. Mycelial processes, x 350. 



9. Basidia and sterigmata. x 350. 



10. Clamp-connections on hyphae in culture, x 300. 

 11-12. Young mycelium from cultures, x 300. 



13-14. Eight-day old mycelium from a culture, x 150. 



15. Cell-formations in culture. X250. 



16. Chlamydospore-formation in a drying culture. X250. 

 17-20. Successive stages in sclerotial-formation in culture. X250. 



21. Young sclerotium in root of Coj^fea foJMS^a. x 100. 



