400 Letters, Announcements, ^r, 



few birds probably ascend to a height of 2000 feet in the air, 

 the vulture tribe excepted. Nearly the whole of its animated 

 inhabitants are likely to be as distinct as its plants. Is it 

 peopled with human beings ? Who can tell ? Why not V 

 The summit, Mr. Brown says, is inaccessible, except by 

 means of balloons. Well, that is a question to be settled on 



the spot between an engineer and a first-rate ' Alpine ' 



But put it that a balloon is required, surely it would be worth 

 while for one of our scientific societies to organize a balloon 

 expedition for the purpose. No one can tell what problems 

 in natural science might not be elucidated. We have here 

 an area of limited extent, within which the secular variation 

 of species by natural selection, if any, must have gone on un- 

 disturbed since, at least, the very beginning of the present 

 age in the world^s life. Can there be a fairer field for the 

 testing of those theories which are occupying men^s minds so 

 much in our days ? " 



We hear with great pleasure that a young ornithologist, 

 already known to fame (Mr. Everard F. im Thurn), has re- 

 ceived the appointment of Director of the Natural-History 

 Museum at Georgetown, Demerara, with liberty to travel 

 and explore for a certain portion of the year. We trust he 

 will turn his attention to the mysteries of Roraima. 



Translation of Milller's Memoir on the Voice-organ of the 

 Passeres. — We are glad to be able to announce the approach- 

 ing publication, by the Delegates of the Oxford University 

 Press, of a translation, by Mr. Bell, of Miiller's Classical Essay 

 upon the organs of voice of the Passeres. Prof. Garrod has 

 undertaken to supply a series of notes to bring the work up 

 to the level of our present knowledge of this important sub- 

 ject. The Academy of Berlin has most liberally granted the 

 use of the original copper-plates, to which, however, we be- 

 lieve, additions will be made. 



