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 — 

 Wliere 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 mesofchorax ; on the metathorax 

 will be seen a pair of small projections, footstalks with a 

 round knob at the top, called haUeres 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 larvse 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 antennae 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 furrows near the month ; wings and halteres most 

 often imperfect or none. The latter group contains only a 



H 



