6 PREFACE. 



previous sources of information R-itter's valuable and 

 learned essay, Die geographische Verbreitung des 

 Kameels, in the thirteenth volume of his Erdkunde, 

 Carbuccia's work on the Dromedary of Algeria, Ham- 

 mer-Purgstall's erudite paper, Das Kamel, in the sixth 

 volume of the Denkschriften der Kaiserlichen Akade- 

 mie der Wissenschaften in Wien, and some other in- 

 structive treatises on the same subject. All these I 

 have used freely, generally referring to chapter or page, 

 though I may, very probably, have sometimes neglected 

 to give credit, particularly in stating facts of almost 

 universal notoriety. To save frequent reference, I re- 

 mark here, once for all, that the passages embraced in 

 quotation marks, without reference to the source, are 

 borrowed from an article entitled " The Desert," in the 

 ninety-first number of the American Whig Review, or 

 from an unpublished journal of eastern travel by the 

 author of that article. I ought also to add, that I have 

 embodied in this volume the contents of a lecture de- 

 livered by me at the Smithsonian Institution in the 

 winter of 1854-5, and printed with one of the Reports 

 of that Institution. 



The results of my own observations have in general 

 accorded with those of previous inquirers. I have not 

 the vanity to suppose that I have added anything to 

 the existing stock of knowledge respecting an animal 



