PATHOLOGY OF YOUNG TREES AND SEEDLINGS. 235 



PLATE XIII. 



Fig. I. Seedling showing mycelium on lower part of stem and on leaves. 



Natural size. 

 Fig. 2. A similar stage, x about 5. 

 Fig. 3. a and b, hyphae ; c, hyphae showing fusion ; d, conidia ; e, part of 



conidiophore (diagrammatic). All x about 950. 



PLATE XIV. 



Part of a small mycelial strand. x about 475. 



Seedling with stem densely covered by mycelium in which the 



young perithecia are partly embedded. x about 3. 

 Seedling with mycelium and perithecia on stem and on the lower 



leaves. Natural size. 

 Part of transverse section of stem, showing a group of hyphae 



penetrating the periderm, x about 100. 

 Transverse section of stem and attached empty perithecium. 



X about 12. 

 Section of perithecium, embedded in mycelium, showing asci and 



spores. X about 40. 



PLATE XV. 



Fig. 10. Parts of two seedlings bound together with mycelium bearing 



perithecia. x about 4. 

 Fig. II. Seedling with mycelium and perithecia. x about 3. 

 Fig. 12. Seedling with mycelium and perithecia. x about 2. 

 Fig. 13. Several perithecia in section, connected by mycelial strands. 



x about 10. 

 Fig. 14. Perithecia on stem of seedling. x about 8. 



PLATE XVI. 



Ascus. X about 430. 



Upper end of immature ascus, showing two spores and thickening 



of wall at apex, x about 475. 

 Upper end of mature ascus, stained with iodine solution, showing 



three spores and the blue thickened apex (shaded), x about 475. 

 Two ascospores, the upper seen with flat side in face view, the 



lower from the side ; each shows two oil drops, x about 950. 

 Two ascospores after soaking in water, showing line on flat 



surface ; the upper seen almost laterally, the lower with fiat 



surface in face view. x about 950. 



All the figures refer to Rosdlinia aquiiaon Ficea exceisa. 



