382 BURMEISTER ON THE SOUND PRODUCED BY INSECTS. 



To conclude, I have to mention in addition to the above, that MM. J. F. 

 Schelver*, Dumerilf, and Chabrier J, are quite of my opinion, even 

 though Schelver differs from me in some unimportant points ; however, 

 neither their observation, nor the theory of the phaenomenon, has been 

 communicated by them with sufficient detail. 



Explanation of the Figures. 



Plate V. Fig. 7. A side view of the thorax of Tabanus bovimis, magni- 

 fied eight times in linear dimension. 



Fig. 8. Horizontal section of the same, in the direction between 

 E D (Fig. 7.), at the same power. 



Fig. 9. Air-hole of Eristalis tenax, magnified forty times. 



* Wiedemann's Archiv, vol. ii. part 2. p. 210. 



f Essai sur le Vol Jes Insects. Paris, 1822, p. 40 seq. 



X Dictionnaire des Sciences Naturelles, vol. i. p. 15. 



[The reader may be amused by referring to The Clouds of Aristophanes, where 

 Socrates is described as engaged in an investigation of this subject. — Edit.] 



