116 



ashore and already in a far state of putrefaction, the bill of which 

 was exactly similar to that of the first. This bird too was moulting 

 from breeding- into winterdress. 



So it seems to happen that the bill of the Razorbill which is 

 moulting into breedingdress, remains without any furrow. And as 

 I dare not suppose that the first one or two furrows arise during 

 the autumn-moult, such a bird will, in its second winter, be believed 

 to be a bird in its first one. This might be the explanation why 

 Razorbills with one or two billfurrows — which seem to be in their 

 second, whereas they may be in their third winter — may have 

 genitals which have been used, so that they might make us believe 

 that the Razorbill now and then breeds already in its first summer. 



I have still been able to give in this article the results of an 

 examination of 230 Guillemots, received November and December 

 .1922, but they have been omitted in the Summary of Material. 

 They bring the total of Guillemots examined up to about 700 and 

 give me the opportunity of adding that old birds which, while assu- 

 ming their springmoult, show a rather strong moult of belly and 

 flanks, are rarely or never to be found among birds received later 

 (see note 2 on page 104), but that they are not rare among birds, 

 received in November and (especially the first half of) December. 

 This indicates that the springmoult of old Guillemots renews less 

 bodyfeathers than that of younger birds, as has already been re- 

 marked. The strong moult of belly and flanks in those old birds 

 which so early assume the breedingdress, is autumn-moult. Further 

 details thereabout will be given later. 



Literature. 



Bebnhard Hantzsch, Beitrag zur Kenntnis der Vogelwelt Islands. Seite 113. 

 Berlin, R. Friedländer & Sohn, 1905. 



E. Hartert, Die Vögel der Palaearktischen Fauna. Seite 1772. Berlin, R. 

 Friedländer & Sohn, 1903—1922. 



0. Kleinschmidt, Berajah 1912. Parus Sahcarius. Fusznote Seite 9. 



0. LE Roi, in Alexander König, Avifauna Spitzbergensis. Bonn 1911. Selbst- 

 ausgabe. Seite 249 und 250. 



S. Samuel, Archiv für path. Anat. Bd I (1871). S. 323. 



Gustav Swenandee, Über die Mauser der Lummen und Alken. Kgl. Norske 

 Vid. Selsk. Skrift 1903, N" 8, 6 pp. Not read bij me. 



H. Weigold, Jahresberichte der Vogelwarte auf Helgoland. Sonderhefte Jour- 

 nal für Ornithologie 1909—1912. 



