PLATE LI 1 1 



Fig. I. — Clematis jackmanni: A vine free from leaf-spot that has been girdled by 

 Ascochyta clematidina in the region of the previous year's stub a. A new shoot would 

 have been sent forth from an active bud at h, but it would have soon died, for the fun- 

 gus had discolored the vascular bundles beyond this point. The presence of the fungus 

 was proved by isolating it from the discolored tissue. 



Fig. 2. — Clematis jackmanni: Plant from which the diseased stub a was cut away 

 without removing the discolored tissue. The leaves were free from leaf -spot and were 

 drying. The split stem shows the discolored fibrovascular bundles from which the 

 fiuigus was isolated. 



