INSECTS. 



487 



forms. The sting is very curiously contrived (see fig. 

 243) ? and enclosed in a sheath, folds up after one or 



Fig. 243. 



1, Head of Culcx pipiens, Female Gnat, detached from the body. 2, Wing. 

 3, A Scale from the Proboscis. 4, Proboscis and Lancets. The reticulation 

 on each side of the head shows the space occupied by the eyes. (The small 

 circles enclose the objects about the natural size. The feather or scale from 

 proboscis is magnified 250 diameters.) 



more of the six lancets have pierced the flesh ; it will 

 inflict a severe though minute wound, the pain of which 

 is increased by an acrid liquor injected into it through a 



