190 INTERNAL ANATOMY OF INSECTS. 



The levator muscles in Coleoptera 9 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 Dynastidtf, but not in Geotrupes, 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 apair of muscles attached to them, which 

 does not agree with his statement 11 . In the Hymenoptera 

 and Diplera 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 . In the Libellulina 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 d . 



Having thus described to you the powerful muscular 

 apparatus by which, either mediately or immediately, 

 the wings 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 



m Chabr.Sur le Voldes Ins. c.ii.333. " Ibid.332. PLATE XXII.Fio. 

 11, 12. c. A ctipuliform process is also observable at the side of the 

 metaphragm. Ibid. FIG. 10. a. c Chabr. Ibid. c. iv. t. xi. 4./. 14. 



d Ibid. c. i. 445. xi.~ 8./. 8, 9. 



