228 The Fermentation of Cacao 



the abdomen being black and the antennae 

 more plumose. 



The colour of the fly is a dusky brownish 

 yellow, and the eyes a bright red to reflected 

 light. The venation of the wings is simple, 

 consisting of five longitudinal and two trans- 

 verse veins, the latter cross between the second 

 and third and the fourth and fifth longitudinals. 

 The eggs are just visible to the naked eye ; 

 they possess two curious prolongations, which 

 are attached to an egg case, and this is 

 easily removable (fig. 2, C and Z7). The larvae 

 are amphipneustic (fig. 2, F). 



The two following experiments show the 

 action of these flies in conveying organisms 

 to cacao : 



(i) Four pods were taken, and two small 

 areas at each end of them were sterilized and 

 a small hole was drilled by a red hot iron. 

 Into these holes sterile glass rods of an eighth 

 of an inch bore were driven and moved freely 

 about, so as to leave a small unoccupied space 

 opposite their entrance on the inside of the 

 pods. In two cases the ends of the rods were 

 protected against the entrance of the flies by 

 tying two or three fibres of thin cotton over 

 them. 



The four pods were now placed in a cage 

 with a large number of these flies, which had 



o 



been obtained from a number of places. On 

 the next day they were seen crawling into the 

 two unprotected tubes and thus into the pods. 



