W. MCRAfc 26& 



containing oospores, it would seem that something other than resting conidia 

 was meant. In 1918 Petch^ describes a bark disease new to Ceylon, the 

 cause of which has not been determined. It is quite different from canker 

 and bark-rot. His description fits exactly with a disease of stems I saw in 

 one of the rubber-growing districts of South India in 1917. I was unable 

 to find the cause. In only two cases did I get a fungus within the 

 diseased bark, and it was Corticium javanicum ; but I do not suggest that 

 it was the cause, and considering the circumstances on the estate I believe it 

 was not. My inability to find a fungus within the bark was also Fetch's 

 experience. It is very likely the same as the brown-bast recorded from Malay 

 as Fetch thinks possible. Feters^ in 1912 described a fruit-rot of Hevea 

 in the Cameroons that was destroying about two-thirds of the fruits, asso- 

 ciating it with the extraordinary rainfall of that year, and the description 

 fits that of the fruit-rot of .South India. His paper is confined to fruit-rot, and 

 no mention is made of any other symptoms on the tree. A Phi/tophthora was 

 found and brought into cu'ture, but no inoculation experiments are recorded. 

 He compared his cultures with cultures of P. Faberi, and decided that the identity 

 of the two fungi was not really settled. Feters did not see an oogonial membrane, 

 and saw antheridia in only two cases. The sporangia come within the Umits of 

 those of P. Meadii, but the oospores are considerably larger. The measurements 

 of only a few spores, 10 — 30 in each case, do not give enough data to enable one 

 to say with certainty whether it is the same as P. Meadii, and Dastur makes 

 the same remark with regard to the identity of this and his Burma Phylophihora » 

 and he considers as resting-spores what Feters calls oospores. Rutgers 3 

 states that Hevea canker occurs in Java, Sumatra and Borneo, and describes 

 the symptoms in four forms, one of which corresponds to bark-rot ; the second 

 to claret-coloured canker ; the third is described thus : In a great number of 

 cases the red canker spots are of small size, but near them in the inner bark, close 

 to the cambium or sometimes in the place of the cambium, is a colouration 

 which is less striking but more widely spread. The colouration shows itself 

 in a section chiefly as yellow, brov/n, or grey stripes and flecks sometimes also 

 as a brown stripe on the place of the cambium. A t\^ical characteristic of 

 the third form of canker is the complete drying up of the section in the region 



iPetch. T. " Hevea Bark Disease." Trop. Afjric, L., pp. U— 17, 1918. 



* Peters. " Uber eine Fruclitlaule von Ileven braailiensii in Kamerun." Ber. uber d. Taligkeit 

 d. Kais. Biol. An.d. iinJahre 1<)11 (Mil. K. B. Anst. Jiir Land timl Forst-wirt'ichajt. No. 12, 1012). 



3 Pvutgens, A. A. L. ■• Jnter'-llubber Congress met Tentoonstellig, Batavia," pp. 4—9, 1914 ; 

 also Rutgers, A. A. L. and Danimermau, K. W. " Ziekten en Be.scliadigingen van //eiea 6/a,<(7/e««i.« 

 op Java." Jlededeelinyen van het Laburalorium voor Pflanleitzickleu, No. 10, pp. 27 — 31, 

 1914. 



