AND PHYSIOLOGY. 



281 



so-called locust is made by rubbing together the anterior pair 

 of wings, upon the nervures or framework of the wings, on 

 which are found file-like edges. In a large species of this 

 kind living in Brazil, w T hich has a drum-like appendage un- 

 der the wings, the sound can be heard a mile ; and if a man 

 of ordinary stature possessed a proportionably loud voice, he 

 could be heard all over the world. 



497. Sounds of Moll use a. — Among the Cepbalopods there 

 are a few individuals which are able to make a clear, bell-like 

 sound, but the origin of it is unknown. 



497. What is said of sounds made t>y molluscs f 



