Letters, Extracts, Notices, b^c. 583 



liberty to try to weld together those ascertained facts by 

 hypothesis. One of the most important matters with which 

 he deals is the existence of mimicry of bird by bird, which 

 is a much more widely spread phenomenon than many persons 

 might be aware of. He arrives at the conclusion that this 

 mimicry is essentially comparable to the colour-mimicry seen 

 in so many animals ; and, moreover, he finds a mimicry of — 

 or rather, we should say, a protective resemblance to — the 

 environment, which has also its analogue in the facts of animal 

 coloration. The cry of the Robin reminds him of the pattering 

 of raindrops ; " the voices of Mallards, Flamingoes, Pelicans, 

 and Herons resemble the croaking of frogs and toads,'' and 

 are therefore less likely to attract unwelcome attentions from 

 birds of prey. We may also add that the note of the Bell- 

 bird has the piu'poseless likeness to the tolling of a bell that 

 the colours of many animals possess to objects which it cannot 

 profit them to imitate. Nor is it certain that in these cases 

 the resemblance of sound has been always produced by an 

 actual effort on the part of the bird itself. The subject is a 

 suggestive one, and is at least as worthy of consideration as 

 the colour-phenomena with which it is sought to compare it. 



L. — Letters, Extracts, Notices, 6^'c. 



We have received the following letters, addressed " to the 

 Editors of ' The Ibis ' '^ :— 



Sirs, — On April 29th last a male of the White-banded 

 Mocking-bird [Mimus triurus, Vieill. ; Scl. & Huds. Arg. 

 Orn. i. p. 8, pi. i.) was shot near here. It is the first example 

 of this species I have met with in this district during 25 

 years. 



I am, 



Yours &c., 



Ernest Gibson. 

 Aj6 (near Cape San Antonio), 

 Buenos Aires. 



May 3rd, 1896. 



