° 1 ' 8 6 J Allen, Gatke's 'Heligoland.'' \ C j 



If his statements are true, not only does an old, long-worn 

 feather receive an influx of pigment, but has its worn and ragged 

 edges restored by the addition of new growths to the edges, — 

 " a restoration of the worn and blunted barbs to their previous 

 entirety." In other words, we must suppose that a feather after 

 months of wear is capable of rejuvenation to the extent of not only 

 developing a system of circulation for the transmission of pigment 

 through the shaft and out into the ultimate divisions of the barbs, 

 but also solid matter for the restoration of the structural parts of 

 the feather which have been worn away by abrasion ! Thus, in 

 speaking of the Spotted Redshank, the Marsh and Wood Sand- 

 pipers, he says the light triangular spots on the margins of the 

 flight feathers and larger feathers of the upper parts " are so 

 little able to stand wear, that by the end of the winter they have 

 almost or entirely disappeared, as a result of which the remain- 

 ing portions of the feathers have acquired jagged edges something 

 like the cutting edge of a saw. It is this edge which, in the 

 course of the colour changes, is restored " (p. 157). 



That such statements can be made seriously by any intelligent 

 ornithologist, and still more be quoted with approval by promi- 

 nent authorities on bird matters (see Auk, XII, p. 346, and Ibis, 

 Jan., 1896, p. 142), is almost beyond belief. In short, it would 

 be hard to find a greater amount of error in an equal space than 

 is crowded into Herr Gatke's fifteen pages on ' Change in Colour 

 of the Plumage of Birds without Moulting,' or more astonishingly 

 absurd statements. 1 



If this is the result of " the most unremitting attention for 

 many years " to this subject at Heligoland, which " supplies us 

 with an abundance of material for observation," we may perhaps 

 reasonably fe^' a little distrust of some of Herr Gatke's observa- 

 tions and conclusions based on " fifty years of investigation " at 



1 It may be added here that this chapter was published in substance by 

 Herr Gatke in 1854, in the 'Journal fiir Ornithologie,' pp. 321-327, in an 

 article entitled ' Einige Beobachtungen iiber Farbenwechsel durch Umfarbung 

 ohne Mauser.' 



For further comment on this paper of Gatke's, and on others of similar 

 character by other authors, see Bull. Am. Mus. Nat. Hist., VIII, 1896, pp. 

 13-44- 



