OF NQBTHTTMBERLAIO) AI7D DITEHAM. 107 



"that such a souiid, but in another tone, is produced, when we 

 experiment with the tail-feathers of other kinds of Snipes. But 

 in S. major, Ca;pensis, and fremata there are four so-called hum- 

 ming feathers on each side, which are considerably shorter than 

 in the species we have been speaking of. Scohpax Javensis has 

 eight on each side, which are extremely narrow, and very stiff." 



The theory appears to be, that, as the bird sweeps downwards 

 in its flight, the outer tail-feathers, having their outer margins 

 advanced, are made to vibrate, or rather their inner webs, with 

 their peculiar rays, are caused to vibrate, and hence the neigh- 

 ing sound. 



I have tiied the experiments described above ; I have blown 

 on the feather, and attached it to a steel wire and a stick as di- 

 rected, but have quite failed to produce the vibrating or neighing 

 sound of the Snipe. "WTien the web of almost any firm feather 

 is blown upon a low vibrating sound can be produced ; and such 

 a sound is stronger than usual when a tail feather of the Com- 

 mon Snipe is used, arising apparently from the fact that the inner 

 web is wide and firm, but the sound is so low that it cannot be 

 heard many yards off. A louder sound is made when the feather 

 is attached to wire ; but I cannot recognise any strong resem- 

 blance it bears to that produced by the bird while descending 

 through the air. In fact, a much nearer approach to this pecu- 

 liar sound can be produced by rapidly waviag backwards and 

 forwards, with short strokes, a cane two or three feet long. 



But the conditions of nature seem very imperfectly complied 

 with in these experiments. In the bird, the tail-feathers are 

 rigidly spread, the inner overlying the outer ones, so that any 

 vibrating motion of the latter must be much restricted, if not 

 entirely subdued, by the inner ones, which must, however much 

 the tail is spread, overlie the others to a considerable extent. 

 The tail-coverts, too, are very long, and will likewise tend ma- 

 terially to retard any such movements of the webs or shafts of 

 the retrices. An isolated feather attached to a long piece of 

 steel wire but feebly represents the same feather in its place in 

 the living bird. Then, while the feather so prepared is di-awn 

 through the air, the arm has to "make some short movements 



I 



