Prof. Blasius uii the Ornitholuyy of Heligoland. 65 



on the cultivation of science. It is certainly no wonder that, 

 when a man like von Homeyer casts his opinion on ornithological 

 matters in the balance, there should be some weight attached 

 to it, and it follows that others may be induced to give it their 

 serious consideration. Every impartial man, it is true, must 

 confess that there is not the slightest substantial reason for 

 suspicion ; but how many people there are who are ready to 

 believe implicitly the assertions of a man of recognized autho- 

 rity ! He, however, who is induced to do this must of neces- 

 sity be ignorant of the facts cited by Gaetke, which may be 

 confirmed by a visit to Heligoland. To save these facts, and to 

 preserve them for the interest of European ornithology, was my 

 duty, the more so as I had the opportunity of verifying and 

 ascertaining them on the very spot. In my opinion, the con- 

 tributions of Gaetke can not only not be doubted, but European 

 ornithology is greatly indebted to him for his persevering re- 

 searches for twenty years in this field. 



I shall, of course, leave to Gaetke, who is now engaged in 

 finishing his Fauna of Heligoland, the task of publishing his 

 own observations himself. But I cannot refrain from pointing 

 out a few of the results obtained by his long and zealous en- 

 deavours, and from adding a few remarks of my own. Amongst 

 the rarities of the European fauna for a locality such as this, the 

 following have been shot in Heligoland : — 



1. Falcg gyrfalco (L.), Schleg. — One of these specimens is 

 the most interesting I ever saw. It is a young bird, in its 

 transitory or moulting state, or passage to the old plumage. It 

 shows that Schlegel was perfectly right in considering the old 

 Norwegian Gyrfalcon as a bird marked and coloured as the old 

 Wandering Falcon. Till now I never met a specimen in which 

 the transition was so clearly to be observed. 



2. Falcg vespertinus, L. 



3. Falcg cenchris, Naumann. 



4. Strix nyctea, L. 



5. Mergps apiaster, L. 



6. HiRUNDG RUFULA, Tcmm. — On comparison of Sicilian 



VOL. IV, F 



