238 



„black rot" are, liowever, often infested afterwards by 

 Chaetotliplodia as a saprophyte, and they thus become 

 covered with the above-mentioned coal-black spores. 



It is clcar, that this may lead one to consider the 

 „brown rot" fungus a more dangerous parasite for the 

 fruits than it really is. This point will be further dealt 

 with below. 



Literature. 



A branch and trunk disease of cacao, with the same 

 symptoms as the one described above, also occurs in other 

 cacao growing districts. In the West Indian Ishmds it 

 is known as „die-back disease". Hère it was investigated 

 and described by Howard'), who observed it in Grenada, 

 St. Lucia, St. Vincent and Dominica. He traced the cause 

 to a fungus, which was determined by Massée at Kew, 

 by means of material sent to him, as Diplodia cacaoicola 

 iîennings. Howard found that the same fungus causes 

 the „brown rot" of the fruits, for not only did the fructi- 

 fications on the branches agrée ciosely with those (tn the 

 fruits, but he was also able to infect fruits with the 

 fungus from branches and conversely to bring about the 

 „die-back disease" in branches by means of spores taken 

 from fruit suffering from „brown-rot". 



He moreover found Diplodia cacaoicola on sugar canes 

 from Demerara and Barbados, and proved by means of 

 infection experiments, that this fungus can also live as a 

 parasite on sugar canes and can thence be transmitted 

 to cacao. 



Barre tt ''), in his discussion of the „Cacoa Pests of 



1) A. Howard. Annals oï Botany. Vol. XV, p. (383, 1901. 

 West-Indian Bulletin. Vol. II, p. 2U3, 1901. 



2) 0. W. B a r r e 1 1. Açricultural Society of Trinidad and To- 

 bago. Society Paper no. 280. 



