THE MOSQUITO 69 



when assisting at a public dinner or when dining 

 in a college hall. 



Three unfed females gave a note of from 

 240 to 270 vibrations. One unfed female 

 gave an abnormally low note of about 175 

 vibrations. Four other females, which were 

 arranged in the order of the distension of the 

 abdomen, after food gave notes correspond- 

 ing to 264-281-297-317 vibrations ; whereas 

 three unfed males all gave exactly the same 

 note corresponding to 880 vibrations. The 

 explanation of the higher note of the males is 

 probably that their wings are markedly nar- 

 rower and shorter than those of the females. 



Whilst working at Anopheles the late Mr. 

 Edwin Wilson, the artist who was drawing 

 our plates, observed at the base of the wing 

 a structure which may possibly account for 

 the tone which is so characteristic a feature 

 of the buzzing. The articulation of the wing 

 with the body is extremely complex. There 

 seems to be a series of structures like minute 

 knuckle-bones articulated with one another, 

 and at the outer end of the series are two 

 ribbed rods which may play some part in the 

 production of the overtones. One is a chitinous 

 bar with some fourteen or fifteen well-marked 

 ridges. In certain circumstances we consider 

 that the other toothed rod can rasp across 

 the ridges of the bar below it. As the wing is 



