Notes. 
J 53 
ON A DISEASE OF COCOA AND COFFEE FRUITS CAUSED BY 
A FUNGUS HITHERTO UNDESCRIBED.— Liberian coffee cultivated in the Gold 
Coast Colony is subject to a disease which attacks the fruit, and which may be so 
prevalent in wet seasons as to endanger the whole crop. 
The first indication of the disease is a dark purplish-brown discoloration of the 
berry, which later becomes covered with a white or pinkish-brown mealy incrustation 
formed by the conidia of a fungus always associated with the disease. 
Fruits of all ages may be attacked, but the disease is most serious in the case of 
young berries, which are arrested in development and eventually become shrivelled and 
hard. 
The same fungus is also responsible for a disease of cocoa fruits. Cross 
inoculations from Liberian coffee to cocoa fruits, and from cocoa to the fruits of 
Liberian coffee, have been effected and have given the characteristic symptoms of the 
disease, from which in both cases the fungus herein described has been reclaimed in 
cultures. 
In natural infections of cocoa the symptoms of the disease—locally known as 
Mealy Pod—are similar to those caused by Phytophthora Faberi, Maub; the point of 
infection becomes brown, the area of discoloration darkens and increases rapidly until, 
given suitable conditions of moisture, the whole pod is involved; the mealy masses of 
conidia, at first white but later tending to become pinkish-brown, which have originally 
emerged as small pustules, form masses so dense that the pod becomes encrusted, and 
the pericarp of the fruit is decomposed. The encrusted masses of conidia are the 
most obvious of the symptoms which distinguish this disease from that caused by 
Phytophthora. 
Such infection experiments as have been conducted have not given conclusive 
results as to the parasitology of the fungus; they tend, however, to indicate that 
it develops much more readily on wounded or moribund fruits than on healthy ones. 
It has never been found on the vegetative parts of its hosts. From an economic point 
of view its occurrence is important, because a large number of pods on a cocoa farm are 
normally wounded by various natural agents, and are thus liable to infection. The 
effect of the disease is particularly serious when young pods are infected, as the 
fungus is able to reach and to destroy the seeds in those cases where the sclerotic 
tissues, found in the fully developed pod, have not been formed. 
The fungus responsible for the disease produces in the tissues of the host a non- 
septate mycelium of comparatively coarse hyphae, which spreads rapidly through the 
intercellular spaces. No haustoria have been observed, but, from the intercellular hyphae> 
branches arise of smaller diameter which penetrate the walls of the host cells, branch 
freely, and pass from cell to cell. The cells thus attacked are killed and their contents 
become discoloured. 
