MISCELLANEOUS NOTES 277 



gain access to its interior until it obtains a means to do so, 

 and so long as the skin of the pod is intact it will not suffer, 

 but as soon as it is injured, even by the bite of a small 

 " pod-hopper " or " thrip," mucilage exudes, the spores 

 can adhere, and infection is made. It would be curious, 

 indeed, if the time of spraying could be arranged to meet 

 the time of the occurrence of all such infections, but as 

 that is evidently impossible, and as the spraying itself has 

 no permanent effect, being readily washed away by tropical 

 rains, it is difficult to see in the method of spraying any 

 effective system for the prevention of fungus infection. 

 Again, as to the various remedies suggested for different 

 pests. These render the work especially difficult for the 

 ordinary manager and overseer, as what is suitable in one 

 place is unsuitable in another, and what would render 

 service in the one case would cause destruction in the 

 other. It has been strongly argued that prevention is 

 better than cure, and that the spraying of cacao pods and 

 the covering them with a thin solution of cupric sul- 

 phate will prevent the attack of fungus disease. This 

 presupposes that there are great quantities of infective 

 material near by from which the infection proceeds, and 

 that no rain falls to wash off the copper. We know that 

 a single infected pod allowed to remain on trees is sufficient 

 to carry infection over a large area ; and surely it would 

 be cheaper and more effective to destroy that source of 

 infection than to spray a whole field to prevent infection. 

 In any case to destroy diseased pods is the first measure 

 to adopt, and spraying would naturally follow in order 

 to destroy any spores which may have been already 

 distributed. 



We know the general methods adopted and the course 

 taken where records are made on sprayed fields. So 

 many fields were sprayed, and so many control plots were 

 marked off, &c. On the control plots many more diseased 

 pods were recorded than on the sprayed sections, and 

 many more pods were ripened on the sprayed sections 

 than on the control plots. From this it is deduced that 



