1889. ] LAWRENCE, Abnormal Coloring of Birds’ Plumage. 47 
come under my notice of abnormal coloring in several species 
of birds. Mr. Ruthven Deane (Vol.I, No. 1, of the Bulletin of 
he Nuttall Orn. Club) has an interesting paper on albinism and 
melanism among North American Birds. The cases to which |] 
am about to call attention would seem to proceed from quite 
a different cause from that producing albinism or melanism. 
In 1862 (Ann. Lyc. of Nat. Hist., Vol. VII, p. 475) I described 
as new a Parrot from Panama, under the name of Pszftovius 
subceruleus ; this specimen, in its general plumage, is of quite a 
uniform pale blue, and in color differs from any other American 
Parrot. 
When Dr. Otto Finsch of the Bremen Museum was preparing 
his great work on the Parrots (‘Die Papageien’) published in 1865, 
he requested to see certain specimens of the family in my collec- 
tion; with this I complied, sending the above-named specimen 
with others. At that time he considered P. subceruleus to be a 
valid species and gave a figure of it in his book. 
In 1871 (Ibis, p. 94) Mr. Salvin says of this specimen: ‘‘Dr. 
Finsch considers this bird to belong to a good species. For my 
own part, without having seen the original specimen, I cannot but 
think that the blue coloring of the plumage is accidental, and due 
to a deficiency in the yellow element of the normally green color 
of the feathers. Mr. McLeannan, who shot the specimen from 
which Mr. Lawrence took his description (the only one, I believe, 
that has ever been obtained) considered it only a variety of B. 
tovz, with individuals of which species he found it associating. I 
notice that in some specimens in our series of 2. fovz, the feathers ~ 
of the back are bluer than in others. B. swbcerulea may only show 
an extreme development of this tendency.” 
Several years have elapsed since this specimen was described, 
and no similar ones have been obtained. 
Mr. Salvin has offered two plausible theories to account for the 
peculiar plumage of this Parrot. 
Since then, what I consider to be a very similar case, has come 
immediately under my notice, which induces me to think there is 
a cause for the last theory advanced by Mr. Salvin. A brood 
of Canary Birds was raised by a member of my family, in 
which there was a great disparity of colors. The male parent 
bird was of a very light yellow, with pure white wings and tail, 
the female was of a dark greenish color (of the variety known as 
