saot perceptibly changed at all (a place 

 where many pin feathers formed). Back 

 altered slightly, rump and scapulars f 

 changed to bright greenish blue, the long 

 russet tips almost entirely changed in some 

 feathers, wings and tail unaltered with the 

 exception of the secondaries and coverts, 

 which had slightly changed on the edges. 

 Throat slightly blackish, lower ventral re- 

 gion as with the rump. Assuming, as we 

 safely may, that the first of February 

 marked the beginning of the macroscopic 

 change, we may attribute the total length 

 of time occupied in the change of some of 

 the breast feathers, from the fall to the 

 spring colors, to a period of about fifty 

 days, which for some of the feathers is an 

 over-estimate. 



It is not a little curious that the feathers 

 should act so independently and especially 

 so when it is considered that each feather 

 comes true in color. 



While skins of birds may serve highly 

 important purposes, it appears essential 

 that for good results in investigations upon 

 color change, one should operate rather upon 

 live birds in confinement. It is quite ab- 

 surd to suppose that a single generation in 

 confinement would so alter the natural laws 

 of the organism as to obscure Aptosochrom- 

 atism or Ptosochromatism, if one process 

 or the other be a natural tendency. It is 

 objectively certain that the phenomenon 

 of Aptosochromatism occurs widely, but 

 whether of individual or specific occurrence 

 is not yet clearly shown. While my bird 

 threw out no hint whatever as to the con- 

 stant occurrence of the color change, it did 

 prove that the ' impossibility ' is possible.* 



* Dr. Chadbourne has informed me, since the above 

 was written, that of three confined male indigo birds 



