MUSICAL CRICKET 



a group intermediate between the Crickets (Achetidse) 

 and the Grasshoppers (Acridiidae). The total length 

 of the body is two inches and a quarter ; when the wings 

 are closed the insect has an inflated vesicular or bladder- 

 like shape, owing to the great convexity of the thin but 

 firm parchmenty wing-cases, and the colour is wholly 

 pale-green. The instrument by which the Tanana pro- 

 duces its music is curiously contrived out of the ordinary 

 nervures of the wing-cases. In each wing-case the inner 

 edge, near its origin, has a horny expansion or lobe ; on 

 one wing this lobe has sharp raised margins ; on the 

 other the strong nervure which traverses the lobe 

 on the under side is crossed by a number of fine sharp 

 furrows like those of a file. When the insect rapidly 

 moves its wings, the file of the one lobe is scraped sharply 

 across the horny margin of the other, thus producing 

 the sounds ; the parchmenty wing-cases and the hollow 

 drum-like space which they enclose assisting to give re- 

 sonance to the tones. The projecting portions of both 

 wing-cases are traversed by a similar strong nervure, but 

 this is scored like a file only in one of them, in the other 

 remaining perfectly smooth. Other species of the family 

 to which the Tanana belongs have similar stridulating 

 organs, but in none are these so highly developed as in 

 this insect ; they exist always in the males only, the 

 other sex having the edges of the wing-cases quite straight 

 and simple. The mode of producing the sounds and their 

 object have been investigated by several authors with 

 regard to certain European species. They are the call- 

 notes of the males. In the common field-cricket of 

 Europe the male has been observed to place itself, in 

 the evening, at the entrance of its burrow, and stridulate 

 until a female approaches, when the louder notes are suc- 

 ceeded by a more subdued tone, whilst the successful 

 musician caresses with his antennas the mate he has won. 

 Any one who will take the trouble may observe a similar 

 proceeding in the common house-cricket. The nature 

 and object of this insect music are more uniform than 

 the structure and situation of the instrument by which 

 it is produced. This differs in each of the three allied 

 families above mentioned. In the crickets the wing- 

 cases are symmetrical ; both have straight edges and 

 sharply-scored nervures adapted to produce the stridu- 

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



