190 INTERNAL ANATOMY OF INSECTS. 
The levator muscles in Coleoptcra, at least in the cock- 
chafer, by a long tendon have their posterior attachment 
in the lower part of the posterior coxae a , their anterior 
attachment to the solid parts to be moved. In the Cock- 
chafer and the Dynastidce, but not in Geotrupes t on each 
side of the cavity of the metathorax under the base of 
the wing is a large and small cupule, which from their 
lateral situation one would think must receive the levator 
muscles — apparently unnoticed by M. Chabrier ; but as 
there is a pair of these cupules on each side, there must 
have been also aj^air of muscles attached to them, which 
does not agree with his statement b . In the Hijmcnoptera 
and Dipiera the anterior attachment of the depressors is 
to the back of the alitrunk and to the prophragm, and 
the levators to the breast, and the sides of the back of 
the trunk c . In the Libelhdina the depressors and leva- 
tors that terminate, by a tendon surmounting a cupule, 
in the base of the wings, have their posterior attachment 
in the breast. These cylindrical muscles with their cu- 
pule and tendon look like so many syringes' 1 . 
Having thus described to you the powerful muscular 
apparatus by which, either mediately or immediately, 
the "doings of insects are moved, it will not be out of place 
if I add a few words upon their Jlight itself. The great 
object in this is to generate a centrifugal force which 
may counteract the weight of the body. Its wings are 
the external organs by which the insect as it were takes 
hold of the air when they fall, and is impelled by it when 
8 Chabr.Swr le Voldes Ins. c.ii.333. b Ibid.2,32. Plate XXII.Fig. 
11, 12, c. A cupuliform process is also observable at the side of the 
metaphragm. Ibid. Fig. 10. a. c Chabr. Ibid. civ. t. xi.— 4./. 14. 
' Bid, c. i. 445. xi.— 8./. 8, 9. 
