6 



plucked one from the body, showed in most 

 cases a decided contrast. Not only were 

 the blue portions dull but their superstruc- 

 tures were gone in many cases, the feathers 

 then being dull brownish. A probable, and, 

 as I am convinced, the truthful source of 

 my bird's extensive loss is found indirectly 

 in the temperament of the bird. From the 

 very first it was fretful and timid, flutter- 

 ing wildly when uncovered in the morning 

 or when the cage was cleaned out. Even an 

 approach in his direction while hanging in 

 the room caused a wild fluttering. Upon 

 such occasions many feathers would be 

 shed, and those remaining were more or less 

 injured. Thus when such a vital process 

 as Aptosochromatism begins to work, these 

 decrepit feathers necessarily would have to 

 be renewed in order to take part in the 

 general plan. The head upon which many 

 pin feathers appeared, naturally received a 

 considerable share of the injury as regards 

 its feathers, and the tail was in a very bad 

 state. 



It will be noticed in the table how gradu- 

 ally the loss began, due doubtless to the 

 gradual approach of activity towards color 

 change in the feathers. It must be ad- 

 mitted that this explanation is purely hy- 

 pothetical, but such a hypothesis, although 

 not of fundamental importance, ofttimes 

 prepares the way for a clearer understand- 

 ing of the problem under consideration. 

 The small loss of down feathers points in 

 two ways to the truth of this assumption. 

 Firstly, being more or less under the con- 

 tour feathers they received less of the wear 

 caused to the others, and secondly, having 

 no color change in themselves, their part in 

 the color- changing process was inconspicu- 

 ous. It is not probable that the bird could 



