DIPTEKA. 81 



Reaumur wished to know how it was that very thick syrups, and 

 even solid sugar, can be sucked up by the soft trunk of the fly. 

 What he saw is wonderful. If a fly meets with too thick a syrup, 

 it can render it sufficiently liquid ; if the sugar is too hard, it can 

 break it into small portions. In fact, there exists in its body a supply 

 of liquid, of which it discharges a drop from the end of its trunk 

 at will, and lets this fall on the sugar which it wishes to dis- 

 solve, or on the syrup it wishes to dilute. A fly, when held 

 between the fingers, often shows, at the end of its trunk, a drop, 

 very fluid and transparent, of this liquid. "The water poured 

 on the syrup," says Reaumur, " would not always insinuate itself 

 sufficiently quick into every part of it ; the .movement of the 

 fly's lips hastens the operation ; the lips turn over, work, and 

 knead it, so that the water can quickly penetrate it, in the same 

 way as one handles and kneads with one's hands a hard paste 

 which it is wished to soften, by causing the water by which it 

 is covered to mix with it. This, again, is the same means the 

 fly employs with sugar. When the trunk is forced to act upon 

 a grain of irregular and rugged form on which it cannot easily 

 fasten, its end distorts itself to seize and hold it. It is some- 

 times very amusing to see how the fly turns over the grain of 

 sugar in different ways ; it appears to play with it as a monkey 

 would with an apple. It is, however, only that it may hold it 

 well in order to moisten it more successfully, and afterwards to 

 pump up the water which has partly dissolved it." 



Reaumur often observed a drop of water at the end of the trunks 

 of flies which were perfectly surfeited with food. This drop 

 went up the trunk, then descended to the end, and that many 

 times in succession. It appeared to him that it was necessary for 

 these insects, as for many quadrupeds, to chew the cud, as it were ; 

 that, in order the better to digest the liquid they had passed into 

 their stomachs, they were obliged to bring it back into the trunk 

 that it might return again better prepared. 



In order to assure himself directly of the reality of his supposi- 

 tion, Reaumur tested the water which a fly, that he says " had got 

 drunk on sugar," had brought back to the end of its trunk ; he 

 found this to be sugar and water. Also, having given a fly currant- 

 jelly, he -observed, after it had sufficiently gorged itself, several 



G 



