The Last Word 271 



drying ceases or becomes delayed. It there- 

 fore becomes necessary to stir and turn the 

 mass frequently, thereby interrupting the con- 

 tinuous working. So far as I can judge by 

 experience, I consider a drying-house supplied 

 with ventilators or fans and rows of trays the 

 most practical method for carrying out the 

 drying process. 



It is very doubtful whether the juice of the 

 pulp can be utilized for the manufacture of 

 vinegar, since, at least under the conditions 

 prevailing in the Cameroons, a very large part 

 of the juice runs off before the cacao reaches 

 the fermenting boxes. 



According to Nicholls the -changes brought 

 about in the interior of the bean are produced 

 by enzymes formed on its exterior ; in this view 

 he coincides with Preyer. The statement can, 

 however, hardly be substantiated. 



The "cacao-fly" or some similar insect also 

 occurs in the Cameroons, as it probably does 

 in all tropical countries. It is always to be 

 found on fermenting saccharine fruits. That 

 it plays an important role in carrying the 

 yeasts is a new and valuable observation for 

 which we have to thank Nicholls. 



Nicholls's proposal, that yeast should be 

 added to the cacao from the first, seems 

 worthy of consideration and of further inves- 

 tigation. Contrary to what Preyer aims at, 

 he does not lay so much stress on using a 

 pure culture (cultivated yeasts) as on increasing 



