314 Birtwell, An Example of Aptosockromatism. \o&.. 



are very incomplete. My intention had been to carry the inves- 

 tigation quite exhaustively into the departments of chemistry, 

 physics and microscopy, feeling certain that each test and experi- 

 ment would intensify the central feature of the subject, but dis- 

 covering that I have acquired phthisis I am compelled to abandon 

 all confining work and leave home for the West. My data, how- 

 ever, may be of assistance to some future worker, who with it, 

 and his own, will be enabled to prove — what so many will not 

 admit, and without full warrant — the repigmentation of a 

 feather after it has assumed the mature condition. Under the 

 circumstances, therefore, the incompleteness of the present paper 

 will kindly be overlooked. 



Anyone who has read Dr. Chadbourne's article (Auk, Oct., 

 1896, and Jan., 1897) upon this subject must have felt keen dis- 

 appointment at the untimely death of the Owls upon which he 

 was working, and it was largely to carry on the unfinished work, 

 that I at once availed myself of the opportunity presented when 

 some excitable Blue Jays betrayed to me the hiding place of a 

 pair of Screech Owls, March 30, 1898. 



The birds were readily taken home and introduced into a shed 

 in which boxes were placed for sleeping and a small cedar tree 

 for perching. The larger bird was in the extreme light gray phase 

 of coloration, the smaller Owl being in the bright red condition. 

 Only the gray bird lived, the other one dying twelve days later. 

 On Dec. 30, 1898, another red bird was captured and placed with 

 the first, but was promptly eaten, so I made no further attempts 

 to obtain another. Both red birds were easily handled, but the 

 marks of the bill and claws of the gray bird were present invari- 

 ably upon my hands after each interview. By stroking the bird's 

 head, however, I could cause it to close both eyes and fall into a 

 state of apparently perfect oblivion from which the plucking of 

 specimen feathers rarely aroused him, thus enabling me to make 

 frequent and careful examinations of the plumage. 



I endeavored to promote as natural conditions for my bird as 

 possible — kept him in the loosely built shed at all times when 

 the weather conditions could be as favorable for my purpose as 

 possible, gave him a mouse or a Sparrow at frequent intervals to 

 regulate him, and gave fresh water for drinking and bathing. 



