291 



spores. Nothing else was noticeable except a trace of young Corticium 

 here and there and a considerable number of the elevated cracks 

 suspiciously like those of Diplodia as figured in the Kew Bulletin. 



I examined these but could find nothing beneath the elevations 

 to suggest that they were due to this fungus. After keeping the 

 sticks, part in my house and part in the office till May I/, nearly all 

 the portions of stem suddenly produced black soot-like masses of 

 spores. The previous night had been very rainy and in the morning 

 the fungus was found to have fruited both in the office and in my 

 house simultaneously. The spores were produced in strings standing 

 erect or curled, or in irregular masses, of considerable size. There 

 could be no doubt of there being those of the fungus called by 

 Massee Diplodia rapax. 



Mr. Patch, in his circular, on the die-back of Hevea braziliensis 

 Jan, IQIO, describes a disease in Ceylon as caused by two fungi. A 

 Gloeosporium which attacks the top shoot and kills it. Then appears 

 a secondary fungus called Botryodiplodia elasticae. This, he says, does 

 not enter the tree till the top shoot has been destroyed. It is the 

 only fungus observable in cases of die-back and causes the death of 

 the tree. 



I cannot say I have seen anything to suggest that the top shoots 

 in the trees affected are attacked by anything but Diplodia, nor do my 

 investigations in this point show this at all. 



Possibly our plant is not identical with the Botryodiplodia of Cey- 

 lon, but it seems likely that the two plants are the same. It will be 

 remembered that Diplodia rapax appeared in Western Africa simul- 

 taneously with its first record in the Malay peninsula. Mr. Petch 

 writes that in 1908 a consignment of Hevea stumps was forwarded 

 from Ceylon to German West Africa, via Hamburg. They were 

 examined there and found to be attacked by a Diplodia which was 

 called Lasiodiplodia nigra. This, he thinks, must be the Botryodiplodia 

 of Ceylon. 



Now, as far as we are aware, no stumps have been sent from the 

 peninsula, certainly not from the Singapore gardens, to Western 

 Africa, so that it looks as if the Diplodia rapax Massee was the same 

 thing as Botryodiplodia, or Lasiodiplodia nigra, and that it got to Africa 

 from Ceylon. 



The Botryodiplodia of Ceylon has not been found to cause serious 

 damage in the cocoa on which it grows in Ceylon, for it seems there 

 to live only on dead stems, but it is otherwise in the West Indies. It 

 has, however, attacked seriously the roots of the tea. 



Mr. Petch's circular on the subject is excellent and important 

 and well worth reading. 



There can be no doubt but that Diplodia is a most dangerous 

 pest whether it requires the assistance of the Gloeosporium to invade 



