462 PBTOH : 



the highest degree probable tliat Diplodia rapax is the same 

 as Botryodi'plodia theobromce. It would be strange indeed if a 

 fungus which is known to gi'ow on Hevea in Ceylon, South 

 India, Burma, and Java, and which is known to be common 

 throughout the tropics, did not occur in Malaya. On that 

 supposition, its occurrence on Hevea on the Gold Coast, a 

 cacao-growing country, is only to be expected. But in spite 

 of its apparent abundance, I have not been able to obtain a 

 specimen of Diplodia rapax, either from Kew or Malaya, atid 

 therefore this point remains undecided. 



The opinions which have been expressed as to the para- 

 sitism of Botryodiplodia theohromce have been for the most 

 part based on an examination of preserved specimens in 

 Europe, and under those circumstances they are of doubtful 

 value. The fungus is a widespread saprophyte, and is seldom 

 absent from dead Cacao or Hevea material : and as it is the 

 m.ost evident fungus on the specimens sent to Europe, all 

 kinds of diseases are attributed to it. No sound pathological 

 work can result from such conditions of investigation, and 

 frequently such work occasions totally erroneous views of the 

 situation. For example, every book which treats of the 

 diseases of tea refers to the serious leaf disease caused by 

 Pestalozzia gnepini : yet, apart from the fact that the fungus 

 is really P. palmarwn, this disease occurs everywhere in tea 

 in Ceylon and does so Httle damage that no steps have ever, 

 to my knowledge, been taken to combat it. Wlien the leaves 

 of a tea bush wither, the planter (as a rule) gathers them 

 and sends them as samples of the disease ; and it would be 

 remarkable if none of the older leaves exhibited the gray 

 patches caused by Pestalozzia. But the buslies may be really 

 suffering from an attack of root disease, of which the withering 

 of the leaves is only a secondary symptom. 



Brick states that Botryodiplodia theohromce is a dangerous 

 parasite of Hevea, Castilloa, and Cacao. In the West Indies, 

 most of the diseases of cacao have been attributed to Botryo- 

 diplodia theohromce , i\\ou^\ Howard's experiments only show 

 that it is a wound parasite, and can attack picked pods if 

 they are wounded. In Surinam, van Hall and Drost. working 

 on the spot, have decided that " The dieback disease of cacao 



