THE GAME BIRDS 01 INDIA, BURMA AND CEYLON. 563 



bored at the other end of the stick and a long string attached. This 

 is whirled round the observer's head and a typical bleat is produced 

 The second outer tail-feathers (sixth pair) produce a fainter sound, 

 though this varies much in individual tails, the others make no 

 sound at all. 



"In order to ensure the success of the experiment it is necessary — 

 (1) that the feathers be placed so that the narrow edge — the outer 

 web — shall encounter the resistance of the air ; (2) that the feather 

 be firmly bound to the pin, so that it cannot turn on its support ; 

 (3) that the string be tied to one end of the stick, so that the 

 long axis of the stick makes an angle with the direction of the 

 string, if I may so put it, so that a vibratory motion is imparted to 

 the stick as a whole, thus simulating the tremulous motion of the 

 snipe's wings during the descent ; (4) lastly, that the apparatus 

 be moved at a uniform rate and not too fast. 



"It is then found that after a period of silence the feathers 

 begin to vibrate : first, the long-drawn-out note, which I may repre- 

 sent as " Whu, Whu, UU, n becomes gradually audible ; it is then 

 succeeded by a series of high and low notes " Bah, Bah, Ah, Ah," 

 resembling the bleat of a young goat, lasting 3-5 seconds, 

 followed by a pause of equal length. This is repeated as long 

 as the apparatus is revolving at a uniform rate. It is found 

 that the individual tail-feathers, of which I collected a good 

 number during the winter, vary considerably both in size, breadth 

 and markings, and, as might be expected, the note produced varies 

 according to their physical characteristics. Thus a long narrow 

 feather produces a sound of far higher pitch than a broader one of 

 the same length. This fact I have noted when comparing the sound 

 made by the several birds when performing the nuptial evolutions 

 over the breeding grounds. To ascertain which part of the fea- 

 thers is essential in the production of the sound, I have cut off the 

 narrow outer web without altering the bleat in any way ; but if the 

 barbs of the inner web be so disarranged that there is a break in 

 their continuity, the web ceases to vibrate and no sound is pro- 

 duced. That the vibration of the inner web is the active causative 

 agent may be seen by the following simple experiments. The 

 feathers are attached to a cork with the outer web held away from 



