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alone; Meves convinced himself that it was due to the outer 
feathers of the tail, which, during the production of the 
sound, is widely extended ; lastly it has been attributed to 
the combined action of the wings and tail. Herr Meves 
demonstrated that the outer feathers of the tail are of special 
form. He also showed that these feathers when attached to 
a piece of wire and rapidly drawn through the air arranged 
in the position they occupy when the tail is widely extended, 
produce a sound almost identical in tone with the natural 
“ humming,’' and that when to the movement of the feathers 
through the air a slight shaking movement is added, the 
resemblance becomes even more striking. Whilst convinced 
of the truth of Herr Meves’ views, so far as they go, my own 
observations lead me to believe that whilst the sound is 
solely produced by the vibration of the inner webs of the 
three or four outer tail feathers, its tremulous character is 
caused by the movement of the secondary feathers of the 
wings, which, by rapidly vibrating in front of the extended 
tail feathers give an intermittent action to the current of 
air which strikes the tail feathers, and hence the terms 
neighing,” or “bleating,” which are often applied to the 
sound. To show the action of an intermittent current of 
air on the tail feathers, I so adapted a vane of feathers to the 
apparatus of Herr Meves, that when drawn through the air, 
by its rotation it alternately interrupted and allowed free 
passage to the air current after the manner I consider the 
secondary feathers of the wing to do.*' The sound pro- 
duced by this arrangement is the closest artificial approxi- 
mation to the natural sound I have ever heard. . In 
conclusion I may remark that the primary wing feathers 
have always appeared to me closed and passive during the 
sound production. 
The Hon. Treasurer, Mr. Mark Stirrup, made an urgent 
appeal (which was liberally responded to by the members 
present) for funds to clear off the Section’s debt. 
* Apparatus exhibited. 
