84 DIPTERA. 



eggs in the ground, she makes use of two scaly 

 pieces in the shape of pincers at the end of her 

 abdomen. During the operation her attitude 

 is very singular. She keeps her body in a ver- 

 tical position, plunging her pincers into the 

 earth ; and having deposited by this means a 

 single egg in the hole, she flies off to make 

 another ; and thus repeats the process, laying 

 a single egg at a time, till the whole are dis- 

 charged from her ovarium. 



The Jgaricm quercinus, whose leather-like 

 substance is found attached to old pales, stumps, 

 and decayed trees, feeds a larva of singular ha- 

 bits, which does not penetrate the substance of 

 the plant, but lives beneath the gills. It has 

 no feet, but a slimy skin, which leaves a trail 

 behind it wherever it moves. It fixes itself to 

 the fungus by a strong glutinous liquor, which 

 it draws from its mouth, and applies in thin 

 laminae one against the other, attaching the ends 

 to an opposite point ; with the same it also 

 forms a little roof for a shelter, so that, when 

 completed, the retreat serves the purpose both 

 of a bed and a tent. Seldom more than eight 



