Photo: J. J. Ward. 



THE PROBOSCIS OF A HOUSE-FLY 



It is a tubular structure ending in two broad pads, traversed by numerous small canals by which 

 saliva from the mouth can be passed out on the surface of the pads. This juice dissolves solid 

 substances like sugar, and the result is sucked up the proboscis. Two unjointed sensitive palps 

 are also shown. When not in use the proboscis is drawn into a hollow beneath the fly's head. 



