120 DWIGHT 



whatever that such change ever can or does occur in the wild 

 state. If caged birds prove anything they prove that under 

 peculiar and abnormal environment the process of moult is 

 curiously suspended or modified by such factors as food, 

 warmth, fright, etc., but if color changes in wild birds are to be 

 explained by what a few captive birds are alleged to have done, 

 there are likely to be sceptics who question the accuracy of 

 such observations. 



The dulness of the plumage of sick birds and subsequent 

 brightening has been noticed, but it is simpler to attribute the 

 improvement rather to the renewal of the neglected oiling and 

 preening than to colors within the feathers themselves. 



Theorists support their arguments by telling us that the color 

 of Canary Birds may be changed by food, but they fail to tell 

 us that the administration of Cayenne pepper must be begun 

 weeks before a moult, the new feathers coming in of a different 

 color from the old. Therefore any bald statement that diet will 

 effect color change in feathers needs to taken with a grain of 

 salt. Sauermann ('89) has made some interesting experiments 

 that any bird-fancier will confirm if questioned. 



Another assertion of theorists is that a feather is not a dead 

 structure, but possessed of some sort of vital connection with 

 the body or capable at least of internal cell activity. Experi- 

 ments with feathers, even while attached to the skin of a living 

 bird, show that mechanical recoloration is possible, but this is 

 no proof- that such a thing can occur except by artificial means. 

 The penetrative power of oils and staining reagents, be the ab- 

 sorbing substance organic or inorganic, is well known and every 

 biologist is aware that dead tissues stain more readily in most 

 cases than living ones. In the case of feathers we are dealing 

 with structures that are (except in the minds of theorists) when 

 mature, cut off from further vital connection with the body, and 

 to assume a re-opening of this connection, or stranger still, a 

 revival of cell activity in dead tissue is simply a tacit confession 

 that the first principles of moult have not been apprehended. 

 Microscopic investigations are always impressive, but they lose 

 force when employed in support of a theory which is not only 

 quite superfluous, but does not even accord with known facts. 



