STRIDULATION OF INSECTS. OOl 



timbals (timbales) of any, and they are only capable of making 

 a very weak song ; most probably, but for the discovery that 

 they possessed these organs, nothing would ever have been 

 heard of the voice of these insects. 



Reaumur thought that the use of the tambours consisted in 

 strengthening the sound produced by the vibration of the 

 timbals, and that they were an essential part of the sonorous 

 organ ; there does not, however, appear to be a good founda- 

 tion for this opinion ; for, from experiments made by M. Solier, 

 (of Marseilles), the Cicada sings or cries just as loud when 

 these parts are pierced or torn. The female is provided with 

 these organs, as well as the male, which is another proof that 

 their function has no direct reference to the song ; it is an 

 organ possessed by the Cicada, of the functions of which we 

 are ignorant. The same observer was led to believe that the 

 air performs an important part in the song of these insects ; 

 he has remarked that the stigma of the metathorax opens 

 directly into the thoracic cavity, instead of opening into the 

 trachea ; so that it may be said that this cavity, which commu- 

 nicates with the abdominal cavity, is nothing more than a great 

 dilatation of the trachea. He thinks that such an organization 

 cannot exist without an object. His observations, which will 

 shortly be published, will doubtless assist much in clearing up 

 what still remains doubtful respecting the song of the Cicada. 



OF OTHER SOUND-PRODUCING INSECTS. 



I have but little more to say on the subject of stridulation ; 

 and if I speak of the sounds produced on certain occasions by 

 some ColeopterouSiHemipterous,Hymenopterous, and Lepidopterous 

 insects, it will be merely to indicate them. These sounds are 

 known to all Entomologists, and present nothing particularly 

 interesting, with the exception of that produced by the Death's- 

 head Sphinx, which is of a peculiar nature, and of which the 

 cause is not yet thoroughly understood ; the others are all very 

 much alike, and are produced by the friction of certain smooth 

 parts of the body. They do not seem to me to be made by the 

 insect with the intention of attracting the female, or of pleasing 

 her; both sexes produce them, and always under constraint, 

 or when in fear, or suffering pain ; at least I have never heard 

 them when the insects have been in a state of entire liberty. 



