STRIDULATION OF INSECTS. 101 



down ; its substance is less membranous than that of the in- 

 struments, and it is covered with rugosities. The bow of the 

 female is placed on the riglit elytron contiguous to the drum, 

 while the situation of that of the male is on the left. On con- 

 sidering the form of the instruments we have just described, it 

 evidently would appear that the insect, in order to produce 

 sounds, must rub its elytra one on the other. During this 

 movement the bow passes over the treble-string and excites 

 vibrations, which are transmitted to the other instruments, and 

 stridulation is the result. The elytra are concealed under the 

 prothorax ; and the insect, when using them, commences 

 by raising the prothorax, in order to allow of their playing 

 more freely, and this he accomplishes by depressing his head 

 and slightly bending the abdomen. The organs of the male 

 are rather more developed than those of the female, and con- 

 sequently produce stronger sounds. 



I have often found in woods and on hedges a grasshopper, 

 the name of which is unknown to me, but which apparently 

 belongs to the genus Anisoptera of Latreille. The male alone 

 possesses elytra, which are very short, though rather longer 

 than those oi Epliippiger. The female may be almost said to 

 be without them, for they are so small as to be recognised 

 with difficulty ; she is mute, and is attracted by the song of the 

 male, whose sonorous organs resemble those of the same sex 

 in Ephippiger. In these the drum may be distinguished, 

 situated on the right elytron (the position of which is always 

 under the left) ; the treble-string formed by the inner border 

 of the drum, and the bow placed under the left elytron. This 

 insect plays on his instrument in the same way as the other 

 grasshoppers, by rubbing the elytra one on the other. 



All the grasshoppers I have seen are provided with an 

 organ, which is peculiar to this family of insects, and which 

 merits attention. It is situated along the prothorax above the 

 coxae of the fore-legs. In order to see it to advantage, it is 

 necessary to raise the lateral borders of the prothorax : we 

 shall then see tw^o cavities in the thorax, somewhat resembling 

 the Phrygian cap in shape. These cavities are lined with a 

 soft hyaline and smooth membrane ; from near the top a tube 

 of the same colour and consistence takes its rise, which is 

 inserted into the thigh and continued to the knee. The cap 

 and tube are readily detached, and separated entirely from the 



