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DIPTERA. 81 
Réaumur 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. Ifa 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 Réaumur, ‘would not always insinuate itself 
sufficiently quick into every part of it; the movement of the 
fly’s lps 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.” 
Réaumur 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, Réaumur 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 
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