136 DWIGHT 



For the excellence of the photographic work I am indebted 

 to the painstaking endeavors of Dr. Edward Leaming and the 

 photomicrographs are unquestionably the best and practically 

 the only ones of feathers that have ever been reproduced. It 

 is needless to specify the difficulties encountered in selecting 

 feathers of similar size to avoid distortion by photographic en- 

 largement and gravure reduction. 



In conclusion, I would say that as I trace out the sequence 

 of moults and plumages in species with which I have been un- 

 familiar, it becomes more and more evident that moult and 

 wear are quite sufficient to explain the most puzzling plumages, 

 and the only problems as yet unsolved are those dealing with 

 birds of which we do not possess enough specimens to link to- 

 gether all the successive plumages into a symmetrical chain. 



TYRANNIC^. 



The Flycatchers offer one of the most puzzling problems of 

 moult to be found among our Passerine birds and the reasons 

 for this are not far to seek. With the exception of two species, 

 M. criuitiis and 5. p]iaiu\ young birds and old migrate south- 

 ward in the fall before moulting, to any marked extent and 

 when they return, show by their plumage that at least one, 

 and in some cases probably two moults have been accomplished 

 during their absence of six or seven months. A few specimens 

 from South and Central America, taken in January and March, 

 show new growing feathers — but the material is, much of it, un- 

 dated and far too scanty to render satisfactory conclusions possi- 

 ble. Another reason may be found in the plumage itself, which 

 does not vary much in color from season to season and close 

 scrutiny of the feathers is required in order to distinguish old from 

 new. The body plumage, too, is soft and of loose texture, even 

 the Juvenal differing little from later stages, so that wear is not 

 very obvious. When, however, suitable material from the 

 tropics is forthcoming, the exact time of moults and their ex- 

 tent will be settled; but until then we must draw inferences 

 largely from the comparative study of plumage. 



