324 Letters, Extracts, Notices, ^c. 



Senckenbergian Catalogue, p. 37, note 70, and others had 

 before me. 



It may seem inconvenient that the same genenc name 

 should occur twice in the same ' Catalogue of Birds,^ but it is 

 ten times better to make one mistake than two mistakes for 

 the sake of appearances only. Besides, a work extending over 

 a period of more than twenty years and prepared by about 

 ten different authors cannot be expected to be entirely uni- 

 form in all its parts, for we are always learning, or at least 

 trying to learn, and to advance in knowledge. 



Lastly, I beg to call attention to the fact that Reichenow's 

 valuable 'List of German Birds,^ so fairly reviewed in 

 the last number of ' The Ibis,' is dated 1889 — that is, five 

 years ago. Unfortunately, the author did not then follow 

 the rules of nomenclature which Count Berlepsch and his 

 associates laid down two years later, and which he follows-now. 

 He therefore would now alter many names which he then 

 used. I am, however, very glad that the reviewer finds fault 

 with Reichenow's big genus Erithacus (including even Ruti- 

 cilla !). I have made remarks on this subject, in accordance 

 with Dr. Sclater's views, in the Senckenbergian Catalogue, 

 p. 1, and in ' Ornith. Monatsberichte,' i. p. 166, and I hope 

 that the Editor's weighty opinion will have a good result. 



I am. 



Yours &c., 



E. Hartert. 



Zoological Museum, Triug, 

 January 29tli, 1894. 



Sir, — Being just now sadly in need of material in the 

 shape of embryos for the purpose of studying the earlier 

 stages of the pterylography of the bird's wiug, I have 

 thought of the plan of writing to ' The Ibis •■ in the hope 

 that, through this channel, I shall be able to reach the sym- 

 pathy of my brother ornithologists during the coming nesting- 

 season, to the end that they may forward me such " hard- 

 set " eggs — or fresh — as they may feel induced to sacrifice 

 to the " cause of science." 



