35 



the new statement, others denied it. But the most striking ob- 

 servation which had come to the knowledge of Di-. Weinland, 

 was made by a friend of his, Mr. Junghaus, of Berlin, on a Blue- 

 throated Warbler, (Sylvia suecica,) which he had in a cage. 

 From June, 1854, till the middle of February, 1855, the throat 

 of this bird, from the bill down to the breast, was pure white ; 

 over the breast ran three bands, blue, black, and yellow, the 

 black one being the narrowest. In the middle of February, the 

 blue band became darker, and spots of the same color appeared 

 all over the white throat, with the exception of a small spot in 

 the centre. On the 21st of February, all the throat was blue 

 except that spot, which remained pure white till the 23d, when 

 it became reddish. On and after the 24th, this reddish color also 

 changed to blue ; but on the 1st of March there appeared again, in 

 the midst of this blue, a lighter spot of beautiful silvery appear- 

 ance ; and it is worth remarking, that this new color began at 

 the basis of the feather, and proceeded outwards. Meanwhile, 

 the black band on the breast had become larger, and shaded 

 insensibly into the blue, while the yellow band remained un- 

 changed through all these mutations. Thus the bird had got its 

 wedding-plumage, without losing one feather, and this it kept 

 through all the reproductive season. At the same time, Dr. 

 Gloger, of Berlin, showed that a very similar observation had 

 been previously made in this country by Audubon, on a male 

 gull, which changed the color of its head, in a fortnight, from 

 gray to the purest black, and, as he supposed, without changing 

 a feather. 



There can be no longer any doubt about the fact ; but the 

 question is, how can a feather change its color, when its blood- 

 vessels and nerves are dried and dead, as is the case with every 

 feather soon after it has reached its full growth. Dr. Weinland 

 had only heard of one explanation, viz : that the wearing away 

 of the fine laminae of the veins of the feather, the so-cqlled 

 pinnul^e, might produce the change of color. This seemed to him 

 not only an unphysiological view of the subject, that a bird 

 should get its wedding-plumage by such a kind of decay of the 

 feather, but, in the cases which he had observed, the changed 

 feathers showed no traces of such a wearing process. The fol- 

 lowing explanation of the fact seemed to him the most natural : 



