F. J. F. SHAW. Ul 



tioiis of liyplia'. Tliey are at first (|uit(' wliite, but later the colour 

 changes to brown, and they become hard and compact. The ma- 

 ture sclerotium is very different to that of R. Solani Klihu. It can 

 easily be seen that it consists of interwoven hypha; (Fig. 1, PI. XI), 

 the structure is uniform throughout, and there is complete absence 

 of any differentiation into cortex and medulla. These large sclero- 

 tia are nmch more obviously composed of pseudo-parenchyma than 

 are the small ones of R. Sola)ii. 



In some diseased ground nut plants certain leaves were coated 

 on the surface with a white layer (PI. V, Fig. 3). Examination of 

 this layer showed it to be composed of closely interwoven hyphte, 

 which were obviously Rhizoctoiiia hyphse. In some parts of the leaf, 

 where this layer was most marked, the lateral branches of the hv- 

 phse were very numerous and peculiar. These branches were short 

 club-shaped structures with a transverse wall some distance from 

 the point of origin, their swollen club-shaped ends often bore from 

 two to four finger-Uke processes, each of which carried a single spore : 

 they were in fact basidia bearing four sterigmata (Text Fig. l\. 4). 

 The spores are hyaline oval structures about 12-10 by 8-6u (PI. 

 X, Figs. 3. 4, 5). This form of fructification was found on the cow 

 pea (PI. V, Fig. 4, ), and on Trichosanthes, in addition to the ground 

 imt ; on all three plants hyphse and sclerotia of the type just described 

 were present. Hyphse are abundant in the tissues of leaves which 

 bear the basidial layer. Infections upon cow pea and ground nut 

 showed that the fungus was a virulent parasite upon both these plants. 

 Seedlings of cow pea were infected both near the growing point 

 and on the hypocotyl, the former taking the more vigorously. The 

 infected area rapidly turns a reddish brown colour, as described in the 

 case of R. Solani, and the tissue becomes soft, the whole plant finally 

 collapsing (PI. IV, Fig. 5). 



In the case of the ground nut, mature plants, bearing nuts, 

 were taken from the field and placed in pots. Infections upon the 

 leaves gave rise, at first, to a white growth of hvphse, which formed 

 later both sclerotia and the characteristic fnuting layer. Hyphse 

 subsequently spread all over the plant, which gradually turned a 



