mSECTS: WINGS AND THEIE APPENDAGES. 105 



ThoTigli he regards these laminae as the cause of hum- 

 ming in bees and flies, he does not decide that other 

 causes may not produce the buzz of cockchafers, &c., in 

 the thoracic spiracles of which he could not discern 

 them.* 



* Man. of Entom. 468. 



5* 



