PASSERINE BIRDS OF NEW YORK 123 



phasis of italics and small capitals is not convincing. While 

 Dr. Chadbourne's paper is a model of exactness in details, the 

 real facts do not bear out his conclusions, nor are his explana- 

 tions the simplest possible. As his evident skill in micro- 

 scopic tecnique will be apt to carry much weight, I have criti- 

 cized his paper at some length because it embodies most of the 

 unsubstantial foundations on which modern theory rests. The 

 views of many of the earlier writers have already been analyzed 

 by Dr. Allen ('96) and need not be specified here. Suffice it 

 to say, therefore, that however pleasing all the various theories 

 may have been they have set aside the following facts : First 

 the normal histology of the feather; Second, the normal moult ; 

 TJiird, the normal sequence of plumages ; and FoiirtJi, the 

 normal effects of wear. A proper comprehension of these four 

 basal facts will entirely eliminate the necessity of abnormal 

 color change while at the same time explaining every plumage 

 easily and naturally. If Nature must be assisted in a perfectly 

 well understood moult by a process of color change about 

 which no two of its champions offer the same explanation, it 

 seems to me that Nature's ability to follow the same laws in all 

 cases is discredited because these champions of supposed new 

 ones have failed to recognize the old. I am not the first to 

 reach these conclusions, but many of my predecessors in the 

 field were much hampered by lack of material to confirm their 

 opinions. Bachman ('39) had a good idea of moult among 

 North American species in spite of some errors. Since his 

 day no comprehensive article touching upon our birds has been 

 written until Mr. Witmer Stone ('96) made clear the different 

 plumages of certain species. I might cite other reliable writers 

 besides these two so far apart in point of time so near together 

 in point of view, but it would serve here no good purpose. 



Years ago a theory was current that Swallows hibernated 

 beneath the mud of ponds. The fact that they could not do it 

 and did not do it is a lesson that our modern color-change the- 

 orists would do well to take to heart. Nowhere among living 

 organisms do restorative changes in tissue take place without 

 destruction or casting off of the old. Consequently belief that 



