382 BURMEISTER ON THE SOUND PRODUCED BY INSECTS. 
To conclude, I have to mention in addition to the above, that MM. J. F. 
Schelver*, Dumeril+, and Chabrier {, are quite of my opinion, even 
though Schelver differs from me in some unimportant points; however, 
neither their observation, nor the theory of the phenomenon, has been 
communicated by them with sufficient detail. 
Explanation of the Figures. 
Piate V. Fig. 7. A side view of the thorax of Tabanus bovinus, magni- 
fied eight times in linear dimension. 
Fig. 8. Horizontal section of the same, in the direction between 
ED (Fig. ’7.), at the same power. 
Fig.9. Air-hole of Hristalis tenax, magnified forty times. 
* Wiedemann’s Archiv, vol. ii. part 2. p. 210. 
+ Essai sur le Vol des Insects. Paris, 1822, p.40 seq. 
+ Dictionnaire des Sciences Naturelles, vol. 1. 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.—Enrr. | 
