DIPTERA. 
97 
wood; he says something like this, for I quote from 
memory:— 
“When wormwood hath seed, get a handful or twain 
To save against March, to make flea to refrain— 
Where chamber is swept and wormwood is strown, 
No flea for his life dare abide to be known.” 
My own experience leads me to believe in the efficacy 
of the strong-smelling wormwood {Artemisia), 
We pass now to the true Diptera , which, as has been 
said, are chiefly characterised by their having only two 
wings attached to the mesothorax ; on the metathorax 
will be seen a pair of small projections, footstalks with a 
round knob at the top, called halteres or poisers ; these 
are also very characteristic, being always present, even 
when the true wings are absent; these organs are 
generally regarded as modifications of the posterior 
wings. What their function is, is not certainly known ; 
Mr. Lowne is disposed to regard them as organs of 
hearing. The larvrn of the Diptera are footless grubs ; 
the order includes an enormous number of species. 
The Order Diptera is divided into two great groups or 
sections, viz., the Proboscidia and the Eproboscidia ; 
in the former, which contains nearly the whole of the 
order, the proboscis is fleshy, ending in a biloped piece ; 
the head is attached to the thorax by a slender neck; 
the antennm are inserted in front of the head, between 
the eyes; wings and halteres developed almost always. 
In the latter section the proboscis is tubular, the head 
sunk in the thorax, showing no distinct neck, antennae 
set in farrows near the mouth ; wings and halteres most 
often imperfect or none. The latter group contains only a 
H 
