VoI.X 



'§93 



Loomis ori Plumage of Some South Carolina Birds. I S S 



larly from the occiput backward ; rectrices, except outer pair, 

 edged exteriorly with blue, and alula, primaries, and primary 

 coverts with bluish ; upper tail-coverts and auriculars tinged with 

 blue, the former tipped with whitish ; sub-apical portions of 

 feathers on breast and sides of neck decidedly bluish ; middle and 

 greater coverts tipped with ferruginous. 



In brief, the blue in these two specimens chiefly prevails about 

 the head, jugulum, rump, and lesser wing-coverts. If the tips of 

 the feathers were worn off in the second specimen as in the first, 

 the concealed blue would be extensively unveiled and a richer 

 attire would result. 



I am constrained to believe that this blue phase represents the 

 adult plumage of the female, and that the plain one generally 

 described in the books is an immature stage, for every season 

 highly colored females have been obtained in numbers fully equal 

 to the adult males of highest feather. Also, plain females and 

 those with but slight traces of blue have occurred in proportion 

 to the more soberly dressed males. Further proof that this high 

 coloration is indicative of maturity is found in the fact that the 

 hornotines I have taken in the fall moult have displayed no sign 

 of it. Failure of sexual vitality has been advanced as an ex- 

 planation in somewhat similar cases. That such physical change 

 is not the cause in the present instance has repeatedly been 

 proven by dissection and by capture of mated birds. A tendency 

 to assumption of the more showy costume of the male has been 

 observed in Passcrina cyanea, Piranga rubra, and Dendroica 

 cczrulescens. It is highly probable that parallels are to be 

 found in many if not all species in which the male and female 

 differ widely in color. It is a question whether the variation in 

 these cases may not be individual. Special investigation in each 

 species alone will decide the matter. 



An immature male with testes partially enlarged, taken May 

 iS, 1S91, has the blue chiefly confined to the sides of the head. 

 In a series, the two females described above would far more 

 readily be picked out as immature males. In the spring of 

 1890 males in full dress were secured from the outset. The 

 following year only those in brown and blue plumage were 

 obtained up to May 19, the last day search was made. Where 

 the deeper colored plumage was concealed by brown tips to 



