PLATR I 



Fig. I. — Phoraa dcstnictiva: Group of pycnidia, with surrounding mycelium, sliow- 

 ing relation of the parasite to the host tissue. P, Pycnidia; M, mycelium; C, cell of 

 host. Drawn by J. F. Brewer. 



Fig. 2. — Phoma destructiva: Single hyphae, showing septation and branching. 

 Drawn by J. F. Brewer. 



Fig. 3. — Phoma destructiva: A few pycnospores highly magnified. Drawn by J. F. 

 Brewer. 



Fig. 4. — Phoma destructiva:-- Pycnidium and surrounding mycelium. Side view, 

 showing spores issuing from ostiolum. Drawn by J. F. Brewer. 



Fig. 5. — Phoma destructiva: Pycnidium as seen in cross section of diseased tissue of 

 tomato fruit. Mass of pycnospores are within pycnidial chamber. Surrounding the 

 pycnidium are cells of host tissue and cut hyphal threads. Drawn by J. F. Brewer. 



Fig. 6. — Phoma destructiva: Pycnidium from artificial culture. Cross section show- 

 ing cell structure of wall, basidia, and pycnospores. Semidiagrammatic drawing by 

 J. F. Brewer. 



Fig. 7. — Phoma destructiva: Pycnidium and surrounding mycelium. View from 

 above, showing ostiolum. Drawn by J. F. Brewer. 



