C'HAT'. VI. BIRDS OF OBYDOS. 253 



sharply-scored nervures adapted to produce the stridu- 

 lation. A distinct portion of their edges is not, there- 

 fore, set apart for the elaboration of a sound-producing 

 instrument. In this family the wing-cases lie flat on 

 the back of the insect, and overlap each other for a con- 

 siderable portion of their extent. In the Locustidse 

 the same members have a sloping position on each side 

 of the body, and do not overlap, except to a small 

 extent near their bases ; it is out of this small portion 

 that the stridulating organ is contrived. Greater re- 

 sonance is given in most species by a thin transparent 

 plate, covered by a membrane, in the centre of the 

 overlapping lobes. In the Grasshoppers (Acridiidse) the 

 wing-cases meet in a straight suture, and the friction 

 of portions of their edges is no longer possible. But 

 Nature exhibits the same fertility of resource here as 

 elsewhere ; and in contriving other methods of supplying 

 the males with an instrument for the production of call- 

 notes indicates the great importance which she attaches 

 to this function. The music in the males of the 

 Acridiidse is produced by the scraping of the long hind 

 thighs against the horny nervures of the outer edges of 

 the wing-cases ; a drum-shaped organ placed in a cavity 

 near the insertion of the thighs being adapted to give 

 resonance to the tones. 



I obtained very few birds at Obydos. There was no 

 scarcity of birds, but they were mostly common Cayenne 

 species. In early morning the woods near my house 

 were quite animated with their songs — an unusual thing 

 in this country. I heard here for the first time the 

 pleasing wild notes of the Carashue, a species of thrush. 



