64 Sphaeronema sp. 



DESCRIPTION OF PLATES 



PLATE IV. 



Fig. (a) Pycnidium and mycelium of Sphaeronema sp. Note the mass of spores at the 



apex of the pycnidium. x about 60. 

 Fig. (b) Apex of pycnidium showing spores and strands, x about 190. 

 Fig. (c) Resting spores of Sphaeronema sp. These occurred commonly during a prolonged 



period of dry weather when no pycnidia were produced, x about 130. 



Fig. (d) Section of infected tissue showing pycnidia and resting spores on the outer surface. 



x about 32. 



PLATE V. 



Fig. (a) Section of infectedcortex showing resting spores formed within the tissue, x about 



200. 

 Fig. (b) Section of wood showing the mycelium of the fungus in the cells. Nuclei are still 



present in some cases, the rest of the cell contents being destroyed, x about 225. 

 Fig. (c) Resting spores produced on artificial medium (nutrient agar jelly) after 8 days. 



x about 100. 

 Fig. (d) Mycelium in cells of diseased cortex, x about 200. 



PLATE VI. 



Fig. 1. Recently tapped surface (A) attacked by the disease. 



The white felt-like masses of mycelium of saprophytic fungi, chiefly Cephalosporium, 

 are irregularly distributed over the decayed surface. The real cause of the disease is 

 more deeply seated and is spreading downwards keeping pace with the tapping. The 

 cortex B-C had been treated with an antiseptic tar mixture several times. Portions 

 of the exposed wood so treated (D) some considerable time after treatment showed 

 irregular white patches. These were due to a granular deposit the result of some 

 chemical action, of the disinfectant cover on the tissues. 



Figs. 2 and 3 illustrate the effect of mouldy rot on a freshly stripped surface. Two portions 

 of cortex were stripped at the same time. 



(a) Was inoculated with spores of Sphaeronema in distilled water, the spores being 



placed on the surface with a soft brush. 



(b) Was not inoculated (control). 



Fig. 2 shows the appearance 24 hours after inoculation. 

 Fig. 3 shows the appearance six days after inoculation. 



Within six days the Sphaeronema had produced pycnidia. It will be noticed 



that on the infected surface, the cortex is utterly destroyed down to the wood. 



Saprophytic fungi are present on the decayed tissue, x about £. 



PLATE VII. 



Fig. 1. Tapped cortex of Hevea attacked by mouldy rot. The disease which started at A 



followed the tapping down to B and is still continuing. 

 Fig. 2. Extension of the disease to new cuts. The disease had almost completely destroyed 



tne tapped surface A-B (over 3 feet). A new cut was then opened at C on a new 



portion, infection quickly followed because the disease was still carrying on all round 



in other trees. The new infection is as previously keeping pace with the tapping 



(C-D). 



Note the large open wounds on the surface A-B, and C-D will show a repetition 



of this. When the new cut started at C is finished, there will be no tappable cortex left 



below 4 ft. from the ground. 



