22 BIRDS AND MAN 



remain permanently distinct. That would naturally 

 be the first conclusion most persons would arrive 

 at, considering that the sound-images which exist 

 in their minds are of the species found in their own 

 country, which they are able to hear occasionally, 

 even if at very long intervals in some cases. My 

 own experience proves that it is not so ; that a man 

 may cut himself off from the bird life he knows, to 

 make his home in another region of the globe thou- 

 sands of miles away, and after a period exceeding 

 a quarter of a century, during which he has become 

 intimate with a wholly different bird life, to find 

 that the old sound-images, which have never been 

 refreshed with new sense-impressions, are as distinct 

 as they ever were, and seem indeed imperishable. 



I confess that, when I think of it, I am astonished 

 myself at such an experience, and to some it must 

 seem almost incredible. It will be said, perhaps, 

 that in the infinite variety of bird- sounds heard 

 anywhere there must be innumerable notes which 

 closely resemble, or are similar to, those of other 

 species in other lands, and, although heard in a 

 different order, the old images of cries and calls and 

 songs are thus indirectly refreshed and kept alive. 

 I do not think that has been any real help to me. 

 Thus, I think of some species which has not been 



