372 INSECT ARCHITECTURE. 



pressed. When this is done to the fly that pro- 

 duces the currant-gall of the oak, the ovipositor may 

 be seen issuing from a sheath in form of a small 

 curved needle, of a chesnut-brown colour, and of a 

 horny substance, and three times as long as it at first 

 appeared. 



Ovipositor of gall-Jly gfcatbj magnijisd. 



What is most remarkable in this ovipositor is, that 

 it is much longer than the whole body of the insect, 

 in whose belly it is lodged in a sheath, and from its 

 horny nature, it cannot be either shortened or length- 

 ened. It is on this account that it is bent into the 

 same curve as the body of the insect. The me- 

 chanism by which this is effected is similar to that 

 of the tongue of a woodpecker {picns), which, 

 though rather short, can be darted out far beyond 

 the beak, by means of the hyoid-bone* being thin and 

 rolled up like the spring of- a watch. The base of 

 the ovipositor of the gall-fly is, in a similar way, 

 placed near the anus, runs along the curvature of the 

 back, makes a turn at tiie breast, and then, following 

 the curve of the belly, appears again near where it 

 originates. We copy trom R aumur his accurate 

 sketch of this remarkable structure. 



* A forked bone at the root of the tongue. 



